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1. Increasing the wave damping effect will decrease the water level response time 10 excellent 1 horrible Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Cumulative days Avg daily error during that 20 day period full scale 0 020 0 033 0 031 0 017 0 018 0 022 0 023 Max daily error during that 20 day period full scale 0 082 0 047 0 064 0 036 0 035 0 076 0 082 Advertised error full scale Other Models The Endress Hauser Prosonic as opposed to the Prosonic T ultrasonic level sensors have an electronics enclosure and display that is separate from the sensor More options are available than for the Prosonic T including measuring spans from 5 meters to 45 meters Either AC power or 24 VDC is needed to run a Prosonic sensor Primary advantages over other ultrasonic sensors Low cost Low power requirement Primary disadvantages over other ultrasonic sensors Confusing instructions Confusing operating matrix Lundahl Ultrasonic 888 525 7300 http www lundahl com Power Power Draw Output Advertised Advertised Lag Temp Cost Supply amp hr day Accuracy Resolution Time Range 10 30 1 7 0 5V 0 2 full 0 13 cm 0 30 615 w VDC at 24 VDC span seconds 60 C software Price includes Se
2. py Datal atalogger penior Datalogger Sensor a n Battery a u External Il External Sensor Power Power NM C D Figure 54 Four basic datalogger layouts Layout A in Figure 54 shows a setup in which the datalogger is powered by its own internal battery but the single 4 20 mA loop must be powered by a separate external power source Layout C is identical except that a 0 5 V sensor output is being recorded instead of 4 20 mA Layout B displays a setup where no external power source is Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 needed which can apply to either a current or voltage sensor output Layout D is typical for larger dataloggers with more than one analog input port Data Transfer and Analysis Dataloggers each require software for configuring the logger downloading data and viewing data The most user friendly packages have Windows based software designed for a specific datalogger Other types of interfaces are DOS based usually text only and can be run on older operating systems and dumb terminal software The later is not device specific and does not perform any data processing but only displays the text output by the datalogger There are four main ways that data is transferred between a datalogger and computer RS 232 ser
3. www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Wiring 9 Q DC Power Source 4 20mA Transmitter u Shield CURS100 TIM e e DC Power Source 0 5 Volt Transducer Shield VDIV2 1 TIM Figure 63 CR10X wiring for a 4 20 mA and a 0 5 V sensor For these specific setups the sensor must be able to handle 12 VDC input Installation Installation of the Campbell Scientific CR10X can be a very difficult task depending on how complex the application is Customer support is very helpful and can prove invaluable to a first time Campbell user To physically install the CR10X mount inside a weatherproof enclosure the optional Campbell enclosure is good Place some desiccant and a humidity indicator inside along with the CR10X The 12 V power supply battery also fits inside the optional enclosure To write a program using ShortCut complete the following quick start steps 1 Install ShortCut by double clicking on the Setup icon 2 Open Shortcut and click OK 3 Click New Pr
4. 30 seconds 3 Em ob oH S amp amp v 5 3 ls B r A m e a Balls E ES 5 D o g g H gt on lov 6 g m H S Hs 9 B8 34 2 9 2 gt S D B Ss a oa elope QD D E D D on 923 S 5685 27 RB SIP 5 2 S x EE 5 9a wos eot amp S 5 z R 9 os sc 25 88 46 A am S 8 d ec Z calf s 2s Rano s 2 e z T B Hu Dr aS o Ag Ag a 3 5 S aello Ed SSH op vo 2 Z a gt S 3 Salo o mAlS Gu 28 0 8 Q 5 6 m Z S 3 8 J 2 s2 ee 8 J O Je T m m 3 ES S 5 H O o g a E 2 S a H amp a w S 5 5 gt O a c 12259 9 7 7 10 Y 8 9 10 5 8 9 5 10 8 10 excellent 1 horrible Cumulative days Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Other Models Digital also manufactures the DPCII which a full control model with relays and alternation schemes which can control up to four pumps The BPC Level Transmitter is a slightly lower model that like the DPCII has two redundant air compressors The BLT is similar to the BLM which was used in this study but has a redundant air compressor and no display or pump relays Primary advantages over
5. Voltage or current output Voltage Current gt 400 per sensor acceptable Intermountain Environmental G FP10C Celesco PT420 Figure 41 Flowchart for selecting a float sensor for a specific application Celesco Float 800 423 5483 http www celesco com Power Power Draw Output Advertised Advertised Lag Temp Cost Supply amp hr day Accuracy Resolution Time Range 12 40 0 3 4 20mA 0 18 full scale Infinite None 40 485 606 depends VDC depends on range 82 C on range Price includes Sensor General Celesco s PT420 cable extension position transducer utilizes the spring loaded setup of Figure 40 in a NEMA 1 enclosure The user must provide a weighted float The Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 spring loaded cable spool is coupled to a potentiometer which varies the current output proportionally with float displacement The spool is designed so that the cable will not over wind wrap over itself which would change the spool s circumference and skew the output Power Anywhere from 12 40 VDC is required to run this sensor While the PT420 is reverse polarity protected if the output wires are switched it does not have any surge protection If the input current exceeds 38 mA the unit must be sent back to the factory for repair Options Several option
6. Sensor output may lag behind a changing water level Extremely dirty water LowDC power draw important Portable datalogging controls unit needed Yes gt 2000 per sensor acceptable Yes 30 sec lag time acceptable Tesco Reactive Air American Sigma 950 Digital 12259 The Campbell Scientific DB1 is not recommended Figure 50 Flowchart for selecting a bubbler sensor for a specific application Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 American Sigma Bubbler 800 635 4567 http www americansigma com Power Power Draw ee Advertised Advertised Lag Time EL Supply amp hr day Pie Resolution 12 VDC or 0 75 w 4 20mA 4 20mA 2 RS232 RS485 0 3cm Infinite 1 minute M w battery a 1 n output includes modem 4 relays 10A 120VAC minimum includes datalogger or 5A 250VAC datalogger Price includes Sensor Datalogger Rechargeable battery General The Sigma 950 is a datalogger unit that is capable of measuring and recording water level or flow bubbler ultrasonic and or submerged pH temperature dissolved oxygen conductivity ORP and or rainfall A graphics display can present data in tabular and graphic formats Many outputs are available including an RS 232 port for direct communication with a laptop or other computer and two opt
7. 85 C 0 2 sec 6x4x9 cm 32 767 readings lithium battery to 0 38 4V 34 min ACR Systems SmartReader Internal 3 6V IAH Y 0 00018 7 8 incl 25mA 200mV 0 5 full scale 45 70 C 0 04 sec 11x7x3 21 500 87 000 or lithium battery temperature 2 5V SV and or 8 hrs cm 1 000 000 readings 10V AGM Electronics Super Puk 9 26 VDC 0 5V 2 Digital 0 10 29 82 C 1 sec 6x8x6 cm 1 930 7 750 readings 1 year depends on date time American Sigma 12 VDC or 3 for water Sigma sensors Depends on 10 1 60 Par 18 000 to 116 000 100 115 230 VAC level sensor 150 C readings Badger Meter 2500 L 12 14 VDC or Badger Meter 0 001 full 0 54 C 1 min 19x14x10 80 640 readings 117 230 VAC ultrasonic sensor scale w o heater 4 25 hrs cm Campbell Scientific CR10X 9 6 16 VDC Y 0 3 1 1 12 voltage 0 2 5mV to 0 5V 0 05 0 25 50 C 0 02 sec 23x9x7 62 000 1 million or 6 current many others 40 C 2 5 hrs cm readings Campbell Scientific CR500 9 6 16 VDC Y 0 3 1 1 4 voltage or 0 2 5mV to 0 5V 0 05 0 25 50 C 0 02 sec 21x4x10 24 000 readings 2 current many others 40 C 2 5 hrs cm Coastal Environmental ZENO 3200 10 7 16 VDC or 0 1 2 4 16 voltage 0 5mV to 0 5V 0 0595 40 70 C 1 sec 1 26x15x10 2 000 2 000 000 Systems 120 240 VAC or 8 current many others day cm readings Dryden 2 9V internal 0 0036 depends on 4 voltage or 0 10 mVDC to 0 0 1 full scale 30 50
8. Power For the 2 wire units only a 12 28 VDC loop is needed to power the sensor and electronics For the 3 wire units a separate 18 30 VDC power supply is required Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Both are reverse polarity protected so that switched wires will not damage the unit While the 3 wire version does not have any delay associated with charging a capacitor it takes more power to run When the 2 wire loop powered unit was tested for time lag none could be easily detected No step response due to the capacitor charging cycle is evident in Figure 38 except at low water levels which is magnified in Figure 39 The measurement interval decreases from around 4 seconds at 4 mA to about 1 second at 20 mA due to a longer capacitor charging time at lower currents A transient suppressor is recommended if AC equipment is used but is not available from Milltronics 120 h eo e eo Adjusted Sensor Output cm 90 0 10 20 30 40 50 60 70 Time minutes Figure 38 Response of Milltronics The Probe to changing water levels Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 o e o o N a Adjusted Sensor Ouput cm o N o 91 5 0 10 20 30 40 50 60 70 Time minutes Figure 39 Step re
9. du 5 o0 son E ae ES Suna 5 5 D S8 EZ gt 5 oo e 9 g S BH 5 72 o c 3 Pes OF 25 o URS o 989 S cz E 38S es 2 95 o E EE 5 gt E S S Sz B L B o o d EZ un Og m 5b so Spe 2 HEZ C Ao o OF 229 lt p Ao e a e ast 6 950 7 10 2 6 7 N Not tested 8 10 excellent 1 horrible Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other dataloggers Communications options Rugged construction Portable Primary disadvantages over other dataloggers Bulky housing Very high price Only uses American Sigma sensors Badger Meter Datalogger 918 836 8411 http www badgermeter com Power Supply Needs External Power Draw Number of Type of Input Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s 12 14 VDC or Y powers sensor 2 1 including the Badger Meter 0 001 0 54 C 1min 117 230 VAC amp logger sensor ultrasonic sensor full scale w o heater 4 25 hrs Size Storage Resolution Date Communi Relays Alarms Local Remote List Price Capacity Time cations Display Operations 19x14x10 80 640 0 001 full Y RS 232 or 4 1A 24VDC or Relays Y Y 2 425 w cm readings scale modem 0 5A 120VAC sensor software Price includes 2500 L datalogger and ultrasonic sensor F
10. Pressure range in PSIG x 0 70 Range in meters 11 Desiccant The vent tube must remain dry necessitating the use of a desiccant or bellows at the open end Desiccant is a chemical that absorbs water vapor Desiccants used with pressure sensors generally change color when in need of replacement As an alternative to desiccant bellows or an air bladder can separate the air within the vent tube from the atmosphere while allowing the pressures to equilibrate Bellows and air bladders do not require any chemicals or maintenance but may adversely affect the sensor reading If they are not perfectly flexible the bellows or air bladder may not expand or contract to exactly the right size needed for pressure equilibration and may also break Absolute pressure sensors do not have vent tubes and therefore require no desiccant and lower maintenance However some type of barometric sensor would be required to provide a reading to the datalogger or PLC where the pressure sensor output can be corrected for changes in atmospheric pressure Installation A submersible pressure sensor is very easy to install simply lower it into a stilling well so that the water intake ports are about 10 cm below the lowest water level that is of interest to monitor To avoid damage to the sensor do not place it where it could go deeper than the overpressure rating An overpressure rating of 3x for a 0 3 m range sensor means that it will be damaged at depths
11. Slimline version can be completely hidden in a 2 inch well of PVC pipe Primary disadvantages over other dataloggers Extreme temperature effects Low reliability Battery very difficult to replace without damaging the unit Intermountain Environmental AquaPod Datalogger 800 948 6236 http www inmtn com Power Needs External Power Draw Number of Type ofInput Accuracy Temp Logging Supply Battery amp hr day Analog Inputs Range Interval s Standard N 0 0012 depends 1 0 2 5V 0 5 25 0 5 sec 9V battery on interval full scale 50 C 24 hrs Size Storage Resolution Date Communi Relays Alarms Local Remote List Price Capacity Time cations Display Operations 12x8x5 2000 8000 or 8 bit Y Cable None Flashing N N 350 w software cm 32000 readings LED depends on memory Price includes AquaPod datalogger BoxCar Pro software for Windows Interface cable Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General The AquaPod is a compact NEMA 4X datalogger that records water level measurements from the Intermountain Environmental float and pulley sensor It is shipped from the factory wired and ready to record the user only has to install the sensor in a stilling well and assemble the float cable and counter weight BoxCar Pro software transfers data to and from the StowAway
12. cem 5 Northwest d i Ta Stevens iS Milltronics E Automata 2 2 Global Water 1 Badger i 3 Druck i A KPSI 78 i Campbell Sigma nd Endresst 4 PVC Water Digital Tesco B Hauser Supply Line I Power Lundahl Garden Distribution Box i Hose I RTU Panel 1 Figure 3 Sensor placement schematic Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Figure 4 Sensor electronics enclosures outside the test tank RTU Panel Data from each 4 20 mA or 0 5 V water level sensor was fed into the four TeleSAFE Micro 16 analog input modules shown in Figure 5 Additionally a Model 5504 Thermocouple input module fed air and water temperature data from 8 type T thermocouples installed inside and above the test tank to the Micro 16 RTU A Model 5401 Digital Input Output I O module allowed for direct pump cycling control with Relay Ladder Logic Programming An Uninterruptible Power Supply UPS inside the RTU enclosure allowed for 4 hours of operation after power loss The enclosure also housed an AC to DC converter for sending DC power lines to the power distribution box All data collected by the Micro 16 was delivered to the control room using Modbus communications protocol via RS 485 serial communication Figure 6 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor
13. Addr Press Enter unless a network of Super Puks is being used Baud Press Enter Date fmt Press 2 for Month Day stamping or 3 for Month Day Year stamping The later takes more memory Time fmt Press 2 for Hour Minute stamping or 3 for Hour Minute Second stamping The later takes more memory Prec Enter a two digit number with the first digit indicating the maximum field width and the second digit indicating the number of decimal places 62 would give outputs like 1234 56 73 would give outputs like 1234 567 Configuration is now complete To download data type DA CM clears all data from the Super Puk memory and RD reads data directly to the computer screen Other commands and configurations are required to set up a network of Super Puks Data Analysis The SCADA software does not perform any data analysis Data can be downloaded in a CSV or binary file format for analysis with other software Test Results The AGM Super Puk is difficult to set up The instructions are very incomplete and confusing and customer service was not much help However if the installation and wiring instructions in this report are followed the Super Puk turns out to Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 be a simple but effective datalogger 4 20 mA readings were off by 3 6 of the full range 8 oN S on go c a e S Gc g Suf D D c
14. Real Goods 1993 Alternative Energy Sourcebook J Schaffer ed Real Goods Trading Corporation Ukiah CA Replogle J A 1997 Practical technologies for irrigation flow control and measurement Irrigation and Drainage Systems 11 241 259 USBR 1997 Water Measurement Manual U S Government Printing Office Denver CO Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Appendices Glossary AC Alternating Current a form of electricity that oscillates back and forth 60 times per second Real Goods 1993 Accuracy ratio of the error to the full scale output or the ratio of the error to the output as specified expressed in percent ASTM 1995 Analog display a real time water level readout on a needle gauge or other analog device Analog I O Input Output a circuit in which the signal can vary continuously between specific limits Lehmkuhl 1998 Communications protocol a set of rules and formats which determine the communications behavior of an entry allowing a meaningful exchange of information Lehmkuhl 1998 This is the language that electronics modules speak to each other in DC Direct Current a steady push of electric current Real Goods 1993 Digital display a real time water level readout on an LCD screen or other digital device Digital I O Input Output a switching circuit that is On of Off
15. fluctuations Is 3 6 month maintenance unacceptable No Bubbler Sensor Ultrasonic Sensor Submersible Sensor Float Sensor Figure 31 Flowchart for choosing the correct type of sensor for a specific application Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 6a Sensor evaluations Performance During Fluctuating Performance During Fluctuating Compatibility with Other Brand Air Temperatures Dataloggers Ability to Read Quickly After Simplicity and Correctness of Water Level Response Time Extended Dry Period Instructions Durability in Dirty Water tel S amp N o o H e 2 amp e m o g D smj ET e lt e0 E a E S a o gt S E DC Power Requirement Long Term Reliability N m Water Level Display Linearity amp Hysteresis Ease of Installation Ease of Calibration Foam Penetration Output Stability 2500 Ultrasonic 1 600 jes 2 c S Sensor Brand Bailey Fischer 50US3000 amp Porter Ultrasonic 1 900 Prosonic T Ultrasonic 585 FMU 230 DCU 7110 615 w software Ultrasonic The Probe 695 Loop Power American 950 Bubbler 7 7 10 Y 10 10 1 NA 4 060 w battery Sigma includes datalogger Campbell DBI Double 1 1 1 1 N 5 10 10 10 10 1 560 w CR510 Scientific Bubbler datalogger Digital 12259 Bubbler 7 7 10 Y 1
16. full scale Max daily error during that 20 day period full scale Advertised error full scale Other Models Campbell Scientific also manufacturers an ultrasonic level sensor the SR50 This sensor must also be used with a Campbell Scientific datalogger and requires a separate air temperature measurement See the Campbell Scientific Ultrasonic section of this report for more details Primary advantages over other bubbler sensors Not affected by water temperature fluctuations Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary disadvantages over other bubbler sensors Very difficult to install and calibrate Nitrogen tank must be replaced every few months Must be used with a Campbell Scientific datalogger Overall poor test results Digital Bubbler 800 335 5219 http www digitalcc com Power Power Draw Output Advertised Advertised Lag Time Cost Supply amp hr day Accuracy Resolution 10 15 2 9 4 20mA RS232 SDI 12 0 25 0 025 0 25 cm 30second 1 200 w VDC 3 relays 15A 125VAC full scale depends on range minimum accuracy option Price includes Sensor Output display High accuracy option Enclosure Rechargeable battery General The Digital 12259 Bubbler Level Monitor System BLM utilizes a single bubbler tube An internal air comp
17. smallest change in the measurand value that can be detected Reverse polarity protection prevents damage to an electronic device when the power leads are switched is wired to and is wired to RTU Remote Terminal Unit a data gathering and control device used to monitor and control digital and analog devices in a SCADA system Basically identical to a PLC Lehmkuhl 1998 SCADA Supervisory Control and Data Acquisition an integrated system of sensors dataloggers controls and communications used for remote monitoring remote manual control and or remote supervisory control Serial communications a digital communications method which allows the simultaneous transfer of numerous pieces of information This is the mode of data transfer such as a type of electric cable not the language UPS Uninterruptible Power Supply a rechargeable battery and charger which give uninterrupted power even in the case of a power outage 194 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf Manufacturer Information ITRC Report No R 99 002 Tucson AZ 85751 2227 ACR Systems Unit 210 12960 84th Ave 800 663 7845 604 591 2252 acr acrsystems com http www acrsystems com Surrey B C Canada V3W 1K7 AGM Electronics P O Box 32227 520 722 1000 520 722 1045 No email No web site American Sigma P O Box 820 Medina NY 14103 0820 800
18. 0 117 Advertised error full scale 1 0 at the tested range Primary advantages over other ultrasonic sensors Higher accuracy during fluctuating air temperatures Performs well even with large waves Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary disadvantages over other ultrasonic sensors AC power only High cost Lag time if extremely fast response in needed Campbell Scientific Ultrasonic 435 753 2342 http www campbellsci com Power Power Draw Output Advertised Advertised Lag Time Temp Cost Supply amp hr day Accuracy Resolution Range 9 16 0 05 6 depends SDI 12 Pulse Train Greater of 1 cm 0 01 cm 3 seconds 45 895 w VDC on interval or serial ASCII Jor 0 4 of distance max 50 C temp sensor Separate external temperature required Price includes SR50 sensor External temperature sensor General The SR50 must be used with a datalogger that can support an SDI 12 pulse train or serial ASCII sensor input basically a Campbell Scientific datalogger A separate air temperature probe must also be hooked up to the datalogger because the SR50 alone does not have any temperature compensation While this method may be more accurate than standard ultrasonic temperature compensation it is inconvenient Primary advantages ove
19. 635 4567 716 798 5599 sigma americansigma com http www americansigma com Tulsa OK 74158 Automata 10551 E Bennett Road 800 994 0380 530 273 0381 automata automata inc com http www automata inc com Grass Valley CA 95945 7806 Badger Meter P O Box 581390 918 836 8411 918 832 9962 jzimmer badgermeter com http www badgermeter com Bailey Fischer amp Porter 125 East County Line Road Warminster PA 18974 215 674 6000 215 674 6740 Webmaster bailey com http www ebpa com Campbell Scientific 815 West 1800 North Logan UT 84321 435 753 2342 435 750 9540 info campbellsci com http www campbellsci com Hampton VA 23666 Celesco Transducer 7800 Deering Avenue 800 423 5483 818 340 1175 On web site http www celesco com Products Canoga Park CA 91309 Coastal Environmental 820 First Avenue South 800 488 8291 206 682 5658 pkelly coastal org http www coastalenvironmental com Systems Seattle WA 98134 Digital Control 10871 75th St North 800 335 5219 727 547 1722 dcc gte net http www digitalcc com Corporation Largo FL 33777 Druck 4 Dunham Drive 203 746 0400 203 746 2494 sales druckinc com http www druck com usa New Fairfield CT 06812 Dryden 6436 Homer Drive 907 344 4995 907 344 8013 No email No web site Instrumentation Anchorage Alaska 99518 Endress Hauser P O Box 246 800 428 434
20. Lehmkuhl 1998 Error algebraic difference between the indicated value and the true value of the measurand ASTM 1995 Full scale output algebraic difference between the outputs at the specified upper and lower limits of the range ASTM 1995 Linearity closeness of a calibration curve to a specified straight line ASTM 1995 HMI Human Machine Interface an operator interface such as a computer terminal which allows the user to interact with a SCADA system Hysteresis maximum difference in output at any measurand value within the specified range when the value is approached first with increasing and then with decreasing measurand ASTM 1995 kHz kilohertz 1000 second A 2 kHz ultrasonic burst emits 2000 sound waves per second Measurand physical quantity property or condition that is measured ASTM 1995 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 PLC Programmable Logic Controller a data gathering and control device used to monitor and control digital and analog devices in a SCADA system Basically identical to an RTU Lehmkuhl 1998 Precision closeness of an output value to the measurand value Repeatability ability of a transducer to reproduce output readings when the same measurand value is applied to consecutively under the same conditions and in the same direction ASTM 1995 Resolution
21. Software extra batteries and a battery charger must also be purchased sss 35 Figure 23 A solar powered compact setup Depending on the sensor a single unit costs about 1135 Software must also be purchased ssssssssssss 35 Figure 24 Series and parallel battery wiring schematics Parallel connections may be unsafe and are not normally advised ie ee rre ex UR QUEE 36 Figure 25 A simple solar electric system adapted from Real Goods 1993 40 Figure 26 PV array installation for a fixed mount sse 40 Figure 27 Setup for pump control with a sensor or datalogger relay 4 Figure 28 Surge protection for a water level sensor The datalogger may require additional surge Protection sc eie erase re ec i i Eq Oe tn Edu A sa dde 42 Figure 29 Proper installation of a stilling well with a flushout tube 44 Figure 30 Basic sensor electronics enclosure i e eoe inen erani IA eee INE S Ip E Rada 46 Figure 31 Flowchart for choosing the correct type of sensor for a specific application 48 Figure 32 Ultrasonic sensor installation eerte eene ener enn nen trennen innen tnn 53 Figure 33 A typical output response of an ultrasonic sensor to air temperature TlaetuatiOfis uice eio aberat et inc d ento Raster oe ES 55 Figure 34 Ultrasonic sensor outputs during wave activity sse 56 Figure 35
22. The DC power source must be within the voltage input range for the sensor een 142 Figure 59 A TrendReader trending graph for the SmartReader Plus 144 Figure 60 Two common Super Puk wiring schematics For this wiring setup the DC power source must be within the voltage range of both the sensor and the datalogget ics deca edo e aaa Lodo d vec ua ir otues a beu Elbe 146 Figure 61 An Insight trending graph for the 950 906 sse 154 Figure 62 A Flars trending graph fot the 2500 L siue asieri oi endi renoyg em retro 158 Figure 63 CR10X wiring for a 4 20 mA and a 0 5 V sensor For these specific setups the sensor must be able to handle 12 VDC input 162 Figure 64 CR510 wiring for a 4 20 mA and a 0 5 V sensor For these specific setups the sensor must be able to handle 12 VDC input 167 Figure 65 A basic ZENO 3200 wiring schematic With this setup the sensor must be able to handle 12 VDC power With other configurations 12 VDC or 5 VDC can be switched to sensors by the datalogger only when needed 171 Figure 66 Linear calibration curve fit for the WL14 sese 179 Figure 67 A daily WL14 cycle due to air temperature changes when not completely submerged The vertical gridlines designate midnight ss 180 Figure 68 A Box
23. an RS 232 serial communication port and an SDI 12 port for connection to a datalogger Power Only 10 15 VDC is required to power the Digital BLM While the air compressor draws 2 A when running the quoted average current is 120 mA 0 12 A This average will change significantly depending on the sample time and how much the water level fluctuates within that sample time Even if the sample time is set at 64 minutes the compressor cycle will still run if the water level changes by at least 2 within any 30 second block Use of the three 15 A relay outputs will also increase power draw Some surge protection is standard but isolation and surge protection of the 4 20 mA loop is recommended Options A sensor unit can be purchased alone for only 775 but the standard system which includes a rechargeable battery and NEMA 4 enclosure costs 1000 For easier reading of the water level display the enclosure can include a window for 50 extra The 200 accuracy option increases the full scale accuracy from 1 to 0 25 An isolation and surge protection package and a solar package are also available Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 The following options are recommended Rechargeable battery and windowed enclosure Increased accuracy The Bubbler Level Transmitter BLT if a display and relays are not needed Installation S
24. display must also be calibrated First open the enclosure door and remove the plastic cover from the back of the display Remove the bubbler tube from the solenoid valve and adjust the offset screws until the display reads the distance between the channel bottom and the bottom of the pressure bell Hook up the bubbler tube to the solenoid valve and press the manual purge button for several seconds until bubbler rise to the surface to clear water from the pressure bell Adjust the span screws until the display reads the current water level and replace the plastic cover Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Maintenance Once a month do a manual purge to check for leaks and problems with the air compressor If the level reading is different before and after the manual purge there is a leak in the system Remove any debris that is hung up on the pressure bell Replace the desiccant in the electronics enclosure as needed Test Results The Reactive Air system was slightly affected by air temperature fluctuations Figure 53 and was the only bubbler system to be significantly affected by water temperature fluctuations Also seen in Figure 53 are the results of a leak in the system due to an incorrectly installed pressure bell The line purged every 12 hours followed by a slow reading change as air leaked from the pressure bell The system displayed ver
25. produces a 4 20 mA output signal As with the Badger Meter a NEMA 4 transducer is connected to a NEMA 4 electronics enclosure by a co axial cable The Bailey transducer is mounted inside a megaphone This ultrasonic sensor only tests the water level about every 8 seconds The sound pulses run in a two part cycle where the water level is tested followed by a test of the air temperature Two averaging circuits determine a water level from 30 distinct pulse readings This results in an approximately 8 second delay for a change in water level Two adjustable alarm relays are standard and a digital or analog water level display is optional All sensor calibration is done with switches on the circuit board Power The 50US3000 can only be run off 110 120 or 220 240 V AC probably the biggest disadvantage to this sensor It draws a maximum of 12 watts An optional surge protector 340 will guard against static discharges Options The only difference between the flow and level meter versions of the 50US3000 is the reference decal inside the electronics enclosure However specifying which version is needed will simplify calibration and re calibration down the line The optional transmitter heater will decrease the minimum operating temperature from 10 C to 25 C Third the user must determine if 120 220 or 240 VAC will be supplied to the unit An analog or digital display is optional The digital display shows an actual depth while the a
26. 100 120 Avg daily error during that 20 day period full scale 0 613 1 294 0 629 1 254 1 247 1 126 Max daily error during that 20 day period full scale 1 446 Advertised error full scale 1 489 1 496 1 648 0 125 for the tested length of time 1 353 1 216 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other submersible pressure sensors Low price Primary disadvantages over other submersible pressure sensors Greatly affected by air temperature fluctuations Greatly affected by water temperature fluctuations Upward facing water inlets clog easily High hysteresis Druck Submersible 203 746 0400 http www druck com usa Power Power Draw Output Advertised Advertised Advertised Lag Overpressure Temp Cost Supply amp hr day Accuracy Thermal Error Resolution Time Rating Range 9 30 0 3 4 20mA 0 06 0 1 0 3 or 0 6 full Infinite None 6xto10x Compen 685 1185 w VDC or or 0 25 span depends on depends on sated enclosure depends 0 100mV full span range range 2 30 C on range accuracy Price includes Sensor STE 110 Sensor Termination Enclosure General The Druck PTX 1230 and PTX 1830 submersible level transmitters have a fully welded titanium constructio
27. 200 w accuracy option Tesco Reactive Air Captive 7 10 Y 7 7 10 10 10 10 10 10 1 NA 2 075 System Air 10 excellent 1 horrible NA not available A adjustable Increasing the wave damping effect will decrease the water level response time Error may have been introduced in the RS 232C to 4 20 mA output conversion Ultrasonic FELIE mm EEEEEE ibid Im tri S EE el amp ER 0 gs B CR S n Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 6b Sensor evaluations continued Performance During Fluctuating Compatibility with Other Brand Air Temperatures Simplicity and Correctness of Dataloggers Sensor Type Instructions Ease of Installation Ease of Calibration Water Level Display Foam Penetration Durability in Dirty Water Ability to Handle Freezing n uj Wave Damping Water Level Response Time Linearity amp Hysteresis Output Stability Ability to Read Quickly After Extended Dry Period DC Power Requirement Overall Rating Celesco PT420 Intermountain G FP10C Environmental Automata LEVEL Submersible 7 10 1 1 SW 10 2 328 w 6 m cable desiccant WATCH Pressure replacement Transmitter Druck PTX Submersible 1 685 1185 w enclosure 1830 Pressure depends on range accuracy Transmitter Global Water WL300 Submersible Pressure Transmitter Instrumentat
28. 4 20 mA sensor s only if the voltage is within the voltage input ranges for both the datalogger and the sensor This means that the sensor must typically be able to handle 12 VDC Several power options are available from Campbell Scientific including rechargeable batteries and solar panels Electrostatic discharge protection is provided in the wiring panel and external voltage protection is available for high risk applications Input The inputs for the CR510 are identical to those for the CR10X except there are fewer channels Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Options The CR510 has the same options as the CR10X except that the memory can not be expanded Additionally multiplexers and SDM devices which expand output and measurement capabilities can not be supported by the CR510 Wiring CURS100 TIM Shield 4 20mA Transmitter Shield DC Power Source Transducer Figure 64 CR510 wiring for a 4 20 mA and a 0 5 V sensor For these specific setups the sensor must be able to handle 12 VDC input Installation Installation of the CR510 is easier than the
29. Accuracy Resolution Time Range 12 14 VDC or 1 1 4 20mA RS 232 4 relays Greater of 0 2 cmor 0 03cm max 8 40 65 C 1 600 117 230 VAC 1A 24VDC or 0 5A 120VAC 0 1 target distance seconds w heater Price includes Sensor Output Display General The Model 2500 consists of a NEMA 4X ultrasonic transmitter unit and a separate electronics enclosure with a 48 character LCD display and front panel keypad About 31 times per second a 60 kHz ultrasonic burst is released from the sensor head and a water level reading is taken However a detection circuit monitors the signal and only outputs level readings within a certain window the last level output a certain level change This safeguard reduces noise in the signal The user can adjust the response time to level changes outside the reading window from 0 to 512 seconds during calibration The water level reading must then remain outside the window for that period of time for the ultrasonic to output that reading as a new water level Along with other features the 2500 includes four programmable relays and a security code Output is a standard 4 20 mA loop Power 117 230 VAC or 12 14 VDC can power this unit When running on DC power an extra battery may be required to power the 4 20 mA output loop The entire setup draws a constant 47mA with no relays activated and up to 60mA with relays Protection against line surges is standard and additional lightnin
30. Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 116 0 115 5 E o 5 e gt o 1150 5 o t Mean Output 114 5 114 0 T T T T T T T T T 0 0 0 2 0 4 0 6 0 8 1 0 1 2 1 4 1 6 1 8 2 0 Time hours Figure 19 A typical sensor output for a stable water level Datalogger Accuracy Setup Each datalogger was wired to a Druck PTX 1830 submersible pressure sensor which was placed in a bucket of water A 12 VDC AC to DC converter powered the datalogger if necessary and sensor loop A Fluke Process Meter 787 amp meter was placed in series with the sensor and set to read 0 30 mA This meter is rated to read 30 mA with 0 05 accuracy and 1 uA resolution For dataloggers that read voltage signals a resistor or current shunt supplied by the manufacturer for that purpose was used Testing The sensor was submerged until an output of approximately 10 mA was reached on the amp meter and waves in the bucket were allowed to settle Readings from the amp meter and datalogger were recorded If the datalogger fluctuated in its output five readings were taken and averaged This process was repeated at an approximately 5 mA output Some datalogger sensor combination units were not tested due to their electronic Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 configurations The AquaPod Datalogger section o
31. Er M ssa 193 Manufacturer Information eii eere etre eerte dehet vr Eee tae 195 Figure 1 The Water Delivery Facility volumetric tank test tank used for water level GETS OR MESO 3 Ae eS oen deus E Et Ue edet E EE 8 Figure 2 Inside view of the empty test tank eese eiie einen etna tnnt tn aen at tae 9 Figure 3 Sensor placement schemniatio aieo tee erede nn terere e ee aides vais 9 Figure 4 Sensor electronics enclosures outside the test tank sss 10 Fig re 5 TeleSAFE RTU panel sioe oca etate Mo Do edo er ubica ibas 11 Figure 6 Sensor Testing Setup at the ITRC Water Delivery Facility 11 Figure 7 Lookout software running on the system computer sss 12 Figure 8 Rectangular weir plate in the test tank Front view showing rectangular spill orifice linearity test points rubber stoppers and clamps regulating the orifice Jr T o P 13 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Figure 9 Sample long term trending results Data points only show the high and the low water level average outputs for every fourth day sss 14 Figure 10 Test Tank Covered with a Canvas Tarp for Air Temperature Testing 15 Figure 11 Sample air temperature fluctuation results ultrasonic sensor 16
32. Figure 12 Water temperature testing setup Entering from the right and above the test pipe are submersible pressure sensor wires bubbler tubes and thermocouple wires Entering from the left is a garden hose eee 17 Figure 13 Sample water temperature fluctuation results submersible sensor 18 Figure 14 Dish soap foam forming beneath an ultrasonic level sensor It was leveled off pior to taking readings aside ud ax ERA EP byte ARE EAT etas IAM x ivre e Tad 19 Figure 15 Sample time lagging output graphed along with the actual water level 20 Figure 16 Hysteresis problems with the Milltronics Probe Error bars are shown at each data point aneas e Lie ees E Cal oes tee Sti bal i s npo at 22 Figure 17 Poor linearity in the Campbell Scientific DB1 Error bars are shown at each point The linearity problems may have been due to the RS 232C to 4 20 mA output converter recommended by the manufacturer sees 23 Figure 18 Offset of submersible pressure sensors due to drying ssssse 24 Figure 19 A typical sensor output for a stable water level sess 25 Figure 20 Two basic sensor setups running on DC power ssssseeeeee 29 Figure 21 Conversion of a 4 20 mA signal to a 1 5 V signal 30 Figure 22 A low power setup which requires battery replacement once per month Depending on the sensor a single unit costs about 1056
33. P E 54 Table 10 Applicable options for the Endress Hauser Prosonic T ultrasonic sensor 68 Table 11 Important fields for basic calibration of the Endress Hauser Prosonic T FMU ipo D E d E c d d m 69 Table 12 Datalogger evaluations ae te eee roe Ecc esu dd ea oet ie 134 Table 13a Datalogger specifications ee eee ete qutt dm pate teer dede 135 Table 13b Datalogger specifications continued sssssseeeeee 136 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 1 Background Equipment Electronic water level sensing equipment is becoming increasingly important for the implementation of water conservation programs in irrigation districts The most important usage of this equipment is found in the following areas a Measurement of water levels upstream and or downstream of canal check structures This is the key information item that is used in modern controllers to control the gate movements Failure or inaccuracies of the sensing equipment in this application can have catastrophic results such as canal overtopping with resulting damages b Measurement of water levels at key remote monitoring points such as regulating reservoirs and tail end canal pools c Measurement of water levels on critical flow measurement devices in irrigation district canals such as flumes or weirs Irrigation districts are increasingly i
34. Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 1 00 70 o 5 095 50 o o o E 5 E E Q o 5 2 8 5 o Lr x 8 0 90 asper eti Aint qi a 30 TY 0 85 10 0 10 20 30 40 50 60 Time hours Sensor Air Temperature Figure 11 Sample air temperature fluctuation results ultrasonic sensor Water Temperature Effects Setup All submersible pressure sensors and bubbler sensors were installed and calibrated inside the 8 inch PVC pipe shown in Figure 12 A garden hose water supply kept the water level constant despite any leaks or evaporation A staff gauge mounted inside the PVC pipe provided a visual reading of the actual water level All submersible sensors and bubbler tubes were secured and weighted if necessary to avoid displacement during testing Two thermocouples were also placed in the water one near the bottom and one at half the total depth All sensors were scaled to engineering units with Lookout software Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Submersible Sensor Wires and Bubbler Tubes we rU con Water Hose Figure 12 Water temperature testing setup Entering from the right and above the test pipe are submersible pressure sensor wires bubbler tubes and thermocouple wires Entering from the left is a garden hose Testin
35. Time Enter the current 24 hour time as HH MM SS such as 23 59 50 15 SiteID Enter a name for the datalogger 16 Analog Delay sec Enter the time period in seconds over which each reading should be averaged 17 Analog Print Enter a name for the analog input such as 4 20mA 18 Digital Print 2 Enter a name for the digital inputs 19 Data D H L Enter the logging interval D in seconds the high alarm H in engineering units and the low alarm L in engineering units such as 1 15 5 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 20 2 22 23 24 25 26 27 28 29 30 ClInp Press Enter unless the lowest and highest analog inputs can be entered i e the sensor is installed and the lowest and highest readable water levels can be obtained quickly ZeroInp Set the zero scale engineering units This value will be approximately the lowest water level that the sensor can read in any units FullInp Set the full scale engineering units This value will be approximately the highest water level that the sensor can read in any units The ZeroInp and FullInp may have to be adjusted until correct readings are obtained Continue Press Enter Config For typical situations where Super Puks are not installed on a network enter 63 for wrap memory or 47 if data should stop recording when the memory is full
36. Type Code to 6 and Field Name to lt D gt lt A gt 28 In the ZENO Program Menu enter E to permanently save the new settings 29 Enter Q to exit the User Menu Lines of data should appear on the terminal screen at the specified logging interval 30 To download all data enter the Data Retrieval Menu from the User Menu and enter The ZENO 3200 program has many options only a few of which were customized in the steps above Though it can take some time the programming can be customized for many different applications The sensor inputs can be averaged calibrated to engineering units and fine tuned in other ways Telemetry alarms relays and analog outputs can also be programmed Maintenance No special maintenance is required for the ZENO 3200 Data Analysis All data analysis must be done with separate software Test Results Because of the many options and settings the ZENO 3200 can be difficult to set up The 74 page user manual which can be confusing should be read completely while setting up the datalogger Once the menus and commands are understood this datalogger is excellent for advanced measurement control data storage and telemetry 4 20 mA readings were within 0 9 full range of the actual current gs gt oD 54 20 gon c ua 2 dc g i un uM zs Syslas 88 at SE JEES Rm E o P on og EE o no oge 8 e4 4 85 o amp o D o amp Ex H o 3908 aa ge e As e Sop a z Oo SS 3 S
37. a standard or optional 4 20 mA output signal Vent Tube 4 Diaphragm gt Figure 43 Basic submersible pressure sensor layouts There are two major methods to read pressure with submersible pressure sensors Keeping in mind that atmospheric pressure changes constantly it averages about 14 7 PSI at sea level Most submersible pressure sensors read gauge pressure Pg or PSIG which is the water pressure above atmospheric pressure such as a tire gauge would read For example the gauge pressure 70 cm below a water surface equals 1 PSIG Since atmospheric pressure varies with location and time gauge pressure sensors have a vent tube in the cable that provides a reference to atmospheric pressure The absolute pressure Pa or PSIA at this depth is 15 7 PSIA since it also includes atmospheric pressure Absolute pressure sensors do not have a vent tube Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 When ordering a submersible pressure sensor the required pressure range must be specified If the water level fluctuates over 3 3 m a 0 5 PSIG transducer might be marginal because it would only provide a 20 cm submergence at the lowest water level However if a 0 10 PSIG sensor was ordered accuracy is reduced See the discussion under Accuracy and Resolution in the chapter on General Information
38. any of the settings the user must select ACCEPT to put the new setting in memory Selecting RETURN always goes back one menu l Apply DC or AC power 2 Press ON 3 Press MAIN MENU 4 Select SETUP then MODIFY SELECTED ITEMS 5 Set Level Units to ft in m or cm 6 Set Primary Device to None Level Only 7 Press MAIN MENU 8 Select OPTIONS then TIME DATE and enter the correct time and date and select ACCEPT 9 Select ADVANCED OPTIONS 4 20mA OUTPUTS CHANGE CHOICE ACCEPT and finally OUTPUT A Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 10 Set the 4 mA input value to the lowest water depth which is of interest to monitor 11 Set the 20 mA input value to the highest water depth which is of interest to monitor 12 Return to the ADVANCED OPTIONS menu and select DATALOG Ifon DC power select the EXTENDED POWER MODE and set the LOGGING INTERVAL if averaging is desired select POWER SAVE MODE 13 Set the MEMORY to WRAP which overwrites old data when the memory is full or SLATE which stops logging and stops outputting a 4 20 mA signal when the memory is full 14 Press LEVEL ADJUST 15 Measure and input the current water level 16 Press RUN 17 Select STATUS Maintenance The internal desiccant module cannot be recharged by heating and must be reordered from Sigma Part No 787 when needed Data Anal
39. at the top keeps it from falling into the well The rim can also be removed so the logger can be dropped into a well with a chain and hook For measuring flows in flumes and weirs the external cable on the slimline version can be replaced with a 1 foot or 3 foot PVC extension Other options include a sewer flow option which helps protect the sensor from fouling and velocity effects a lift station option which has more openings in the sensor cover screen and a pressure pipe option which comes with a stainless steel casing and 3 4 inch NPT male thread The HP200LX palmtop computer 800 can be used to download data instead of a laptop Wiring The WL14 comes wired from the factory Installation Install the sensor as described in the Global Water Submersible section of this report Do not install the PVC housing slimline version or datalogger where they are exposed to direct sunlight Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 To configure the WL14 from a PC running Windows complete the following quick start steps l 2 00 m ON Uh 10 Plug the interface cable into the jack on the WL14 and connect the other end to a PC Insert the EZLevel diskette into the PC and double click on the Setup icon The program will install automatically into c Ezlevel Close the setup window once installation is complete click the X in the upper
40. be purchased as a separate unit from the 2500 for 225 extra Wiring No wiring is required for the 2500 L datalogger Refer to the 2500 instruction manual for wiring the ultrasonic sensor Installation The 2500 L is contained in a NEMA 4X enclosure and can be mounted on a vertical surface To configure the 2500 L with Flars for Windows complete the following quick start steps 1 Configure the ultrasonic sensor as described in the instruction manual using the front panel keypad and LCD display The datalogger cannot be configured from the 2500 L front panel 2 Connect the interface cable to the port on the lower side of the 2500 L and connect the other end to a computer 3 Insert Disk 1 and double click on the Setup icon Follow the installation instructions Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 4 Open Flars Click OK when the introduction box appears in the center of the screen 5 If COMI is not being used choose Setup Port from the Defaults menu Choose the correct COM port and click OK From the File menu choose Setup Click Time Set to synchronize the datalogger clock with the time on the computer Click Get to download the factory settings O 0 ug Make sure that only Digital 1 is checked and the correct Fullscale value for the ultrasonic sensor is entered i e 25 for a 0 25 foot range sensor Enter a Chann
41. d 3 amp 2 Jo e al al E E EIS 5 8 O 9 E Ey S 9 5 8 d a H g ps a o 5 5 E O a am 950 6 7 7 10 Y 9 9 10 10 9 7 8 NA 8 10 excellent 1 horrible NA not available Other Models The Sigma 960 flow meter is identical to the 950 except that it has an extended 150 day battery life 90 day for the 950 and comes standard with an internal modem Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other bubbler sensors Low power requirement when 4 20 mA output is not used Easy to install and calibrate Primary disadvantages over other bubbler sensors High list price because of datalogging capabilities No4 20 mA output possible when running on DC power Campbell Scientific Bubbler 435 753 2342 http www campbellsci com Power Power Draw Output Advertised Advertised Lag Cost Supply amp hr day Accuracy Resolution Time 12 2 9 Radiometric CS 0 05 0 045 em depends 60 1 560 w CR510 VDC datalogger only full scale on range seconds datalogger Price includes DBI sensor CRS510 datalogger General The Campbell Scientific DB1 Level Sensor was the only double bubbler system tested It utilizes three solenoid valves to route three pressure lines to a single pressure transducer A compressed gas
42. for 15 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Power A 9 30 VDC excitation is needed at the sensor Several output options are available including 4 20 mA The surge protection option will protect the unit from a 10 000 amp surge Options The Series 200S and 720 are identical 0 25 static accuracy 595 as are the Series 210S and 730 0 1 static accuracy 695 If accuracy is not critical the Series 710 0 5 static accuracy 495 and Series 700 1 0 static accuracy 395 are also available The output options for all these models include ratiometric 0 100 mV 0 5 V and 4 20 mA Any range from 0 2 through 0 300 PSIG can be specified A 12 inch MNPT conduit attachment can be installed on the cable side of the sensor One of three applicable removable nose cap options must be specified Use the open faced cap for dirty water and the closed faced cap for clean water A 14 inch MNPT nose cap is also available When ordering also specify the length of polyurethane jacketed cable needed The Tefzel jacketed cable and the optional titanium housing are only needed when organic solvents are present Either desiccant or the aneroid bellows are required to keep moisture out of the vent tube The bellows does not require any maintenance but will slightly affect the quality of the sensor output If corrosion is a probl
43. from the same company as the water level sensor In other cases the sensor must be accompanied by a datalogger recorder that is from the same company The Need When an irrigation district has a need for a water level sensor there tends to be a large yet incomplete endeavor to search for information on the part of irrigation district personnel Often the district expends several years of effort before it decides to standardize on one type of sensor In some cases there are so many problems with the sensor or datalogging equipment that the district abandons its efforts to measure water levels or flow rates ITRC has provided many districts with assistance in their search for information on water level sensors The Provo Utah and Denver Colorado offices of the USBR have experimented with a few sensors What were lacking however were a side by side unbiased and standardized comparison of the performance of a wide range of sensors and datalogging recording equipment in outdoor conditions and the dissemination of the results Not only did many sensor designs need to be tested many brands also needed to be compared Irrigation districts need specific guidance on costs advantages disadvantages required support equipment and required maintenance for the various options Furthermore it will be very helpful to have one local centralized location at which the available hardware and configurations are displayed For these reasons the Wat
44. horrible Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Other Models If a 0 100 mV output is desired the PDCR 1230 has a 0 25 full scale accuracy and the PDCR 1830 has a 0 1 full scale accuracy If only a 42 inch Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 inner diameter stilling well is available the PDCR 35 D has a 0 39 inch 1 0 cm outer diameter The SCU 220 can then be used outside the stilling well to convert the 0 100 mV signal to 4 20 mA The PTX 1290 has an elastomeric diaphragm to prevent clogging from silt Primary advantages over other submersible pressure sensors Excellent performance during fluctuating water temperatures Rugged construction Primary disadvantages over other submersible pressure sensors Large termination enclosure usually needed Global Water Submersible 800 876 1172 http www globalw com Power Power Draw Output Advertised Advertised Advertised Lag Overpressure Temp Cost Supply amp hr day Accuracy Thermal Error Resolution Time Rating Range 10 36 0 3 4 20mA 0 2 full Included in Infinite None 4x Compen 495 VDC span accuracy sated 2 21 C Price includes Sensor General The Gl
45. is proportional to water level Figure 49 shows the three basic layouts for bubbler pressure sensors Nitrogen Tank or Air Compressor Nitrogen Tank or Nitrogen Tank or Air Compressor Air Compressor a Valve Pressure Valves i Pressure Valve Pressure d Transducer Transducer d Transducer Bubbler Double Bubbler Captive Air Figure 49 Basic bubbler pressure sensor layouts Each type may or may not have a valve that controls atmospheric pressure referencing The diagram on the left side in Figure 49 displays a standard bubbler system An air compressor which periodically pressurizes a small reservoir or a large compressed air tank usually nitrogen continually forces air down the bubbler tube and out into the water The sensor can continuously measure the pressure in the bubbler line Some Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 systems have the ability to purge the line with a large blast of air to keep debris out When this occurs a solenoid valve keeps the pressure sensor from being damaged Some type of atmospheric reference must be made in order to compensate for changes in the atmospheric pressure Often it is just a hole on one side of
46. level The span and zero settings consist of four switches each with the decimal point fixed in the center X X X X for inches and after the third digit XXX X for centimeters Make sure to calibrate in inches or centimeters not feet or meters For example to set the span at 102 centimeters set the four switches at 1 0 2 and 0 from left to right With a digital display any units can be used Simply determine the current depth and adjust the switches to get the correct reading in the desired units Maintenance To maintain the Bailey Fisher amp Porter periodically remove any spider webs from inside the megaphone and re calibrate Test Results The sensor tests the air temperature about every 8 seconds This is accomplished with the use of a small tab which is installed in the factory at a specific distance from the transducer face A series of quick pulses are sent out and the time for the sound waves to return to the face is used to electronically compensate water level readings for changes in air temperature This method of temperature compensation which is unique among the sensors tested for this project all others use a thermistor or similar electronic device increased performance during fluctuating air temperatures Figures 33 and 37 The averaging circuits in the 50US3000 effectively drowned out much of the noise due to waves on the water surface Figure 34 The sensor was not able to penetrate foam but linearity and hyste
47. memory module graphs data and exports data to other programs for further analysis Onset Computer Corportation 508 759 9500 manufacturers the datalogger electronics used in the AquaPod Power The entire setup including the water level sensor only requires one standard 9V alkaline battery The battery comes with the datalogger and will last up to one year depending on how often data is retrieved This can be replaced with a 9V lithium battery which can be found at most electronics stores Lithium batteries last about twice as long as alkaline but are often more than twice as expensive Input The AquaPod powers the sensor output loop and records the voltage across the potentiometer Any sensor that has a 0 2 5 V potentiometer output could potentially be wired into the AquaPod but it is configured specifically for the Intermountain Environmental float and pulley sensor Options Measurement ranges of 91 152 and 305 cm are available The datalogger range corresponds to the float sensor range Memory ranges of 2000 8000 or 32000 data points are also optional If a portable computer is not available for downloading data in the field extra memory modules can be purchased about 200 depending on memory size Memory modules can be exchanged in the field and the data downloaded later onto a desktop computer If the logger will be mounted more than 1 m away from the sensor extra cable should be ordered or the user must
48. metal bubbler tubes with the small 90 angles must be bolted together tightly with the supplied washers and bolts to fix the separation distance Fasten the metal tubes to a fixed structure Mount the DB1 along with the datalogger and power supply in an enclosure It is possible to mount the bubbler assembly separate from the datalogger but the voltage signal may be affected at distances greater than the 100 feet It is better to route the bubbler tubing over that distance The user must supply 0 25 in outer diameter tubing of the appropriate length Purchase or rent a nitrogen bottle and automatic pressure relieved regulator from a welding supply store or other vendor Strap the bottle to a fixed structure to keep it from falling over Open the nitrogen bottle valve and set the regulator at or just above 10 PSI Adjust the needle valves on the bubbler assembly so that 1 3 bubbles leave each tube per second Follow the wiring schematic in the DB1 instruction manual Once the DB1 and datalogger are all set up the datalogger must be programmed Refer to the Campbell Scientific Datalogger sections of this report for details Maintenance Every 2 3 months or when the nitrogen runs out replace the nitrogen bottle Also inspect the valves and tubing for leaks and replace the desiccant if needed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Te
49. org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Maintenance Keep the datalogger enclosure free of moisture Desiccant packs are available from Campbell Scientific Data Analysis PC208W does have a report generating feature but the data is often easier to analyze using Excel or other spreadsheet software Data is saved as a CSV file unless otherwise specified by the user Test Results The Campbell Scientific CR10X is very difficult to use especially the first time If an application is outside the scope of ShortCut the user must program the datalogger using Edlog Campbell Scientific s programming language The large volume of reading material that comes with the CR10X is not very useful Only the ShortCut software allows the user to configure the datalogger for simple uses without complete confusion On the other hand the CR10X is very adaptable and has a wide range of potential uses if user spends the time to figure out how to apply them 4 20 mA readings were within 0 02 full range of the actual current Uu On 5x4 ob o o amp oo 4 og S 5 o0 a o Es 5 p oz os gt z g o END o 9 9 3 e 5B eo o S o o e 8 u H o o5 as pa m as o E Sg a z O E as 3 S5 BS B D o 3 SebBug m Q S m 5b SO ob 2 z D eg e Ao o Ok 28265 lt D a i c Ds O S8 oo A a o CR10X 1 2 2 10 N 10 5 10 excellent 1 horrible Primary advantages over other datalogg
50. other bubbler sensors Long term reliability Low list price Primary disadvantages over other bubbler sensors 30 second minimum lag time Tesco Bubbler 916 395 8800 No web site Power Power Draw Output Advertised Advertised Lag Cost Supply amp hr day Accuracy Resolution Time 12 VDC or 12 0 4 20mA 0 32 cm Infinite None 2 075 120 VAC depends on depth Price includes Sensor Output display General Tesco s Reactive Air Level Monitor is a captive air system which eliminates the need for constant bubbling A pressure bell basically short PVC pipe with a cap on top is attached to the underwater end of the bubbler tubing see Figure 49 in the bubbler sensor overview The purge interval and length set with dipswitches on the circuit board determine how often the pressure bell air is replenished If the compressor stops operating the sensor can still measure the water level for up to 30 days with decreasing accuracy as the air is dissolved in the water Except during a purge a pressure Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 transducer continuously determines the water level The transducer has a small port for reference to atmospheric pressure An LCD display indicates the water level and a manual purge button is located next to the display The electronics enclosure does not have a NE
51. powered compact setup Depending on the sensor a single unit costs about 1135 Software must also be purchased Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 3 Components for a sample solar powered compact setup Purchased From ACR OWL 500 ACR 800 663 7845 299 Datalogger Milltronics Loop Powered Milltronics 817 277 3543 695 Probe Ultrasonic Sensor Power Sonic 12V 1 2AH Power Sonic 650 364 5001 17 Sealed Battery Representative Suncycler 8A Charge Real Goods 800 762 7325 50 Controller Uni Solar 5W Solar Panel Real Goods 800 762 7325 69 1130 Batteries Voltage To determine the required battery voltage all parts of the power loop must be taken into consideration The sensor datalogger wiring and all other devices have resistance to electrical flow To maintain a certain current equation 2 shows that voltage must increase with increasing resistance Ifa sensor has a specified excitation of 12 30 VDC at least 12 VDC must be available across the sensing element A 12 V battery would not be sufficient if any significant length of wire was involved or if any additional loads such as a datalogger were placed on the system If batteries are placed in series their voltages are additive Figure 24 Connecting batteries in parallel can be unsafe and is not advised unless absolutely required
52. submenu Run through the System Setup submenu altering the password if desired OpMode set to LOW POWER unless on AC power Storage CIRCULATE will over right the oldest data when the memory is full and Card Use set to COPY ONLY unless using a card for primary memory The other submenu items can be ignored initially The AxSys MPU is now configured to read a single 4 20 mA input To return to the factory settings turn power OFF and the hold down MENU while turning the power ON Maintenance If operating in humid conditions place a bag or two of desiccant between the clear plastic lid and the front panel Replace the desiccant as needed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Data Analysis Data can be download directly from the AxSys MPU using Logterm software LT exe Stevens Data Viewer Support Software STDV exe must be used to retrieve data from a data card To download data directly from the AxSys MPU complete the following quick start steps 1 Connect the AxSys MPU to a computer using a standard RS 232 cable 2 Copy the contents of the Stevens Utility Software diskette onto a computer and open the Logterm program 3 Check that the comport settings listed above the menu are correct The normal settings are 9600 baud 7 databits 1 stopbit and even E parity 4 Type 4 to begin a standard column data dump 5 Press Enter
53. supply usually a 225 ft nitrogen bottle with pressure regulator bleeds a constant air flow into two submerged lines that are installed at a fixed vertical distance apart The sensor reads the pressure at both depths then measures atmospheric pressure with the third pressure line A second reading is taken from one of the submerged tubes to get a depth reading The average of 20 25 measurements is then recorded by the datalogger resulting in a 1 minute time lag The DB1 double bubbler must be used with a Campbell Scientific datalogger Power The Campbell Scientific datalogger supplies 12 VDC to the bubbler system The manufacturer recommends AC power or a solar panel in conjunction with a rechargeable Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 battery due to the considerable power requirements compared to other sensors The bubbler system relies on surge protection in the datalogger Options Three pressure ranges are available 5 15 and 30 PSI 3 5 10 6 and 21 1 meters Metal bubbler tubes are optional for easier installation Installation The user must determine the distance between the two bubbler tubes They should be as far apart as possible but the upper tube must always be submerged This means that difference should equal about 20 30 cm less than the lowest anticipated water depth The lower ends of the two optional
54. supply 4 wire cable Wiring The AquaPod comes wired from the factory Installation For permanent installation remove the AquaPod s cover and insert screws or bolts through the four mounting holes in the rear corners of the enclosure The Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 housing is rated NEMA 4X but should be enclosed in an additional shelter to extend the life of the datalogger The logger can be installed up to 30 m away from the sensor but the sensor output may be affected since it is a voltage rather than a mA signal To configure the AquaPod in Windows complete the following quick start steps 1 Plug the interface cable into the jack on the AquaPod and connect the other end to a PC 2 Insert the BoxCar Pro diskette in drive a and double click on the Install icon Follow the installation steps 3 Open BoxCar 4 From the Logger menu select Launch The Launch window will appear 5 Select the appropriate Duration To the right of the duration box the sample interval for that duration will be displayed 6 Select the appropriate units in the Measure box 7 Click on Wrap around when full if data should continue logging when the memory is full 8 Click Start to load the new settings 9 From the Logger menu select Readout to download data from the logger After data is retrieved the logger must be launched again to c
55. temporary or permanent site Data from up to three water level or flow sensors can be logged simultaneously along with other data such as temperature and rainfall The bulky but rugged NEMA 4X 6 dataloggers have a keypad and LCD graphics display The 950 960 is compatible only with Sigma sensors Power for both the datalogger and sensors are provided by a rechargeable Sigma battery or an AC jack Power The 950 can either be run off a 12 VDC battery or AC power Lead acid gel and Nicad rechargeable batteries are optional If running off AC a power converter must be purchased The datalogger is always drawing power but the amount can vary widely When the display is up and running 250 300 mA is being drawn but when the display is out only 1mA is needed If the 950 is run off a battery it must be set to extended power mode so that the display will remain shut down when not in use No surge protection is available Input Only specific American Sigma sensors can be used with the 950 960 Options The 950 and 960 are identical except that the 960 has a longer battery life 150 instead of 90 days and comes standard with an internal modem For DC power the rechargeable gel battery 135 has a longer life and is cheaper than the Nicad battery 200 If AC power is available order an AC power supply converter AC power backup or a wall mounted battery charger for portable testing For permanent installations where AC power is not availa
56. the pressure transducer In the center layout in Figure 49 two bubbler tubes are used instead of just one The submerged ends must be installed a specific vertical distance apart and air bleeds out of them at a constant rate Before each measurement a double bubbler calculates the pressure difference between the two tubes and calibrates itself Then a reading from either one of the submerged tubes is taken and compared to an atmospheric pressure reading to yield a final output The self calibrating routine results in some unavoidable lag time A captive air system is not a true bubbler because air is not continuously forced down the submerged tube Instead a large reservoir of air is maintained below the surface by periodic purges These purges also act to clear out any solids build up During a purge a solenoid valve must isolate the pressure sensor from the pressure line in order to avoid damage A large change in outside water level results in a small change in the fluid level within the bell due to the compressibility of the air The complete pressure change is transmitted to the sensor just as with the other unit The larger the bell volume the higher the measurement accuracy and the more air required for purging In theory a captive air system should be able to monitor water levels in relatively clean water without purging for a month or more The accuracy of the sensor would be slightly affected as the air dissolved in the surroundin
57. the time and date are not correct the PC s internal clock must be adjusted Click the Send Setup button 10 To download data click the Back Up button in the OWL Status window The datalogger can be configured for a delayed start for configuration away from the measurement site Low and high trigger alarms can cause the optical port to blink when activated The OWL can be re calibrated to match voltage or current readings with the actual values Data Analysis TrendReader will automatically graph data in the format of Figure 57 and put data in a table CSV files can also be generated Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 mA ACR OWL Info Logger DC Current 13 0 20mA DC 8 5 7 0 5 5 8 59 10 8 59 20 8 59 30 8 59 40 8 59 50 9 00 00 9 00 10 9 00 20 9 00 30 9 00 40 9 00 50 AM AM AM AM AM AM AM AM AM AM AM 1124 98 11 2498 11 24 08 11 24 98 11 2498 11 2498 11 2498 11 2498 11 2498 11 24 98 11 24 98 Figure 57 A TrendReader trending graph for the OWL Test Results The ACR OWL was very easy to set up and install 4 20 mA readings were within 0 8 full range of the actual current Q H Boe s E v jy TE B e A n 9 989 B SE 5 EB gt E a gt os gt z g o amp n D o 2 9 S p o 8 8 o as g amp og E Xu 5 Aog SS 3 a S bv o2 o T aes DEl D d B o Sue 9 S ESS SIAB g SE gee lt gt OWL 500 8 9 9 10 0
58. water A stilling well may be required If echo is lost may display a misleading reading Large beam angles cannot be used in constricted spaces Some sensors damaged by flooding i e they are not waterproof Some delay between the time when power is first applied and the first output 58 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 4 20 mA 0 5V 4 20 mA or 0 5 V output Not Important Low DC power draw important Is gt 1000 per sensor acceptable Yes 8 second lag time acceptable Yes Extreme air temp fluctuations Yes Significant foam possible Greater than 1 accuracy acceptable Yes Yes Ease of use important AC power available gt 600 per sensor acceptable Yes Bailey Fischer amp Porter 50US3000 Endress Hauser Prosonic T FMU 230 Lundahl DCU 7110 Badger Meter Milltronics 2500 The Probe Figure 36 Flowchart for selecting an ultrasonic sensor for a specific application Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Badger Meter Ultrasonic 918 836 8411 http www badgermeter com Power Supply Power Draw Output Advertised Advertised Lag Temp Cost amp hr day
59. with lead acid batteries Can tolerate freezing Need periodic toxic electrolyte changes Real Goods 1993 Maintenance Maintenance of storage batteries involves replacing the electrolyte in Nicad batteries and refilling the water in lead acid batteries 1f needed sealed lead acid do not need to be refilled Also the battery contacts must be kept clean if the contacts corrode or get dirty they can be brushed with a wire brush Most importantly maintaining a good charging cycle will greatly increase battery life Begin to recharge before the battery drops to 20 of its charge Recharge until it is completely full Real Goods 1993 Safety Safety is critical when working on batteries sulfuric acid and hydrogen gas is a dangerous combination Baking soda neutralizes battery acid so some should be readily available when working on unsealed lead acid batteries Never allow flame or spark near a battery and do not put electrical components in the same compartment DC powered solenoid switches and motors often spark If they are in the same enclosure as the battery an explosion is likely It is safer to put batteries in series than in parallel Real Goods 1993 Solar Power General A common way to charge batteries in the field is with a photovoltaic PV system PV cells which are made of stacks of silicon based layers produce approximately 0 45 volts each during maximum sun exposure These cells are connected Water Level S
60. 0 98 12 10 98 12 1098 12 10 98 Figure 59 A TrendReader trending graph for the SmartReader Plus Test Results The ACR SmartReader was very easy to set up and install 4 20 mA readings were within 0 3 full range of the actual current GH on g95 S ug E S Sue e Sun ga D 0 a S Be gt 5 a o 4 9 tg 3 oO n 5 5 Dog oZ zg o a D o g e S c BES gf eer 9 amp 8 e amp 8 B XL 5 S r E as 3 a amp B9 qo e D 9 S ae ET me oO amp Gi bb O Oo 58 5 BE S Qo o o Seo lt D 298 a O SHA z oo A a O SmartReader Plus 8 6 9 10 N 10 9 10 excellent 1 horrible Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other dataloggers Upto seven 4 20 mA or 0 5 inputs Easy to use Compact size Primary disadvantages over other dataloggers No control capabilities AGM Datalogger 520 722 1000 No web site Power Needs External Power Draw Number of Type of Input Accuracy Temp Logging Supply Battery amp hr day Analog Inputs Range Interval s 9 26 Y 0 3 1 0 5V 2 Digital 0 1 29 Isec VDC 82 C 1 year Size Storage Capacity Resolution Date Communi Relays Alarms Local Remote List DEC cations DEP Open Price 6x8x6 1 930 7 750 8 bit RS 2320r 2drycontacts Relays 425 w readings depends RS
61. 00 output for a constant water level and temperature a E ob GH S H H o z 9 A E 3 5 g 9 b o n o g 2 p ie ue as Bals e ps 95 E B is ES E 8 5858 2 9 2 gt ts 94 8 n ESIERIrx E a A of 9 R E EE Og a nS e amp 4 e 2 E B 3 E E z 828 Jalg E2 E amp A g 8 IF e S BE 52 2FIZ8le 9 1G e sg gt Bs Gq as a As A gt D pP 3 5 B Fas Paleo IAI 85 8s 8 18 e 18 18 E Jt Iz 3 8 B 9 a4 e 2 55 3 E 3 l o on S Ez 3 Sassi o o S a g a a 3 E es z a S S amp l JE JEF EG 4 IR A B E I J S 3 JA n D D z m o e A WL300 10 9 10 N 9 3 1 10 9 5 1 9 2 5 10 excellent 1 horrible Cumulative days Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Other Models Global Water also offers the WL14 a self powered sensor and datalogger that is discussed in the datalogger section of this report Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other submersible pressure sensors Highlong term accuracy Desiccant not required but recommended Primary disadvantages over other submersible pressure sensors Poor performance during fluctuating water tem
62. 10 e a Water depth cm eo oO a walang m 5 8 8 E E 5 90 J 8 n2 mB m amp n mn2 mRA 3 8 a 85 M 80 i 5 25 98 6 14 98 7 4 98 7 24 98 8 13 98 9 2 98 9 22 98 10 12 98 Time High Water Level l Low Water Level Figure 48 Long term drift in the Instrumentation Northwest sensor calibration H Es Es 5 S i 2 8 2 bs gt E E 2 548 E 3 2 fa 9 S 38 3485 z o o ES m amp Sls BS iESIES E 5 o S 8 E BEIS O8 2 w eR 5 8 128 lg B 3 e 3 z 58 8 s8l2 8 8 88A 2 I2 S E IS e 3 IO 3 4 ESEE 3 BE ls c m a A E c BE le BAS JAZAS Y gt USE I2 5 5 E aglo Bs iA oe lo E gt 2 B m E B o Sig s EB j2e 28le 8 3 2 8 a 6 2 3 uz 3 salas g a 9 o 3 e g T m E E E EZ IS 5 g a O 9 E S S 5 S H T a g ps a 2 S 5 D e o zu A PS9800 10 9 10 N 10 5 10 10 8 9 fe ES 7 8 10 excellent 1 horrible Cumulative days Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Other Models The PS9105 375 is a passive ratiometric device It has a very low typical excitation voltage of 2 5 V and is typically used with the Campbell Scientific CR10X datalogger For 75 an enhanced calibration can be run on the sensor and programmed into
63. 15 AC power sources should be protected with a UPS Uninterruptible Power Supply Stilling Wells General Water level readings taken inside an open channel are often incorrect due to waves turbulent fluctuations and or floating debris such as foam or weeds A stilling well which is connected to the channel by a pipe gives a more accurate average reading Polyvinyl chloride polyethylene and galvanized iron pipes sealed on the lower end make good wells The well must be securely anchored to prevent oscillations from being introduced within the well USBR 1997 Sizing For actively changing systems most control cases the connecting pipe must be large enough to allow the stilling well to equilibrate quickly Table 4 gives several examples Stilling well diameter 8 Access tube diameter 8 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 4 Stilling well dimensions for actively changing systems Stilling well inside Minimum access tube diameter inches inside diameter inches 12 1 16 2 20 2 24 3 30 4 36 4 48 6 An oversized pipe can also be used with a gate valve to allow adjustment to the required amount of dampening The gate valve must have the same head loss for flow in both directions It should be centered on the pipe so that a length of at least 20 pipe diameters ex
64. 32 interface The SC32A requires a 9 pin to 25 pin computer serial cable 2 Connect the 12 V leads to the Power In terminal connectors on the CR10X 3 Install PC208W by double clicking on the Setup icon Open PC208W 4 Click Setup If using a port besides COMI click Add COM Port until the correct port number appears 5 Click Add Device Choose CR10X Datalogger and highlight the correct COM port Click OK 6 Click Save Edits the close the Setup Connection window click the X in the upper right hand corner 7 Click Connect If the computer is connected to the datalogger correctly it should set up a connection automatically 8 Click Set Datalogger Clock to synchronize the datalogger date and time with that on the computer 9 Click Send to load the program written in ShortCut onto the datalogger Click OK find the ShortCut program and highlight it Click OK Once the transfer is complete click OK again 10 Current data can be viewed with the Launch Graphics buttons or on the Numeric Display sheet the white tab at the bottom of the window 11 Click Collect to download data from the datalogger Click Browse enter a file name and find the folder where it should be saved Click OK then OK again Data will be saved in a CSV format PC208W unlike PC200W can handle telecommunications The software can automatically call the logger s and download data Water Level Sensor and Datalogger Testing and Demonstration www itrc
65. 4 317 535 8498 On web site http www endress com Greenwood IN 46142 0246 Global Water 11257 Coloma Road 800 876 1172 916 638 3270 globalw globalw com http www globalw com Gold River CA 95670 Instrumentation 14972 NE 31st Circle 800 776 9355 425 867 0404 info inwusa com http www inwusa com Northwest Redmond WA 98052 Intermountain 601 West 1700 South Suite B 800 948 6236 435 755 0794 info inmtn com http www inmtn com Environmental Logan UT 84321 6219 KPSI 34 Research Drive 800 328 3665 757 865 8744 kpsi cts com http www kpsi com Lundahl Instruments 429 South Main Logan UT 84321 888 525 7300 801 753 7490 solution lundahl com http www lundahl com Milltronics 709 Stadium Drive Arlington TX 76011 817 277 3543 817 277 3894 raulc g milltronics com http www milltronics com Stevens Water Monitoring Systems P O Box 688 Beaverton OR 97075 0688 800 452 5272 503 469 8100 info stevenswater com http www stevenswater com Tesco Controls 3434 52nd Avenue Sacramento CA 95823 916 395 8800 916 394 1893 No email No web site 195 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 196
66. 485 0 5A 28VDC or software on date time stamp 0 5A 28VAC Price includes SPM 9000 D2N Super Puk SCADA software free General The Super Puk is a very simple device but it can be difficult to use The standard model has 1 analog 0 5 V input which can also monitor a 4 20 mA signal 2 digital inputs and 2 dry relay contacts A network of low cost Super Puk datalogger can be used to monitor single sensor inputs at many locations However the instructions and software are out of date and difficult to use Power A 9 26 VDC external power supply is required for the Super Puk The same power supply can be used to power the 4 20 mA or 0 5 V sensor only if the voltage is Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 within the voltage input ranges for both the datalogger and the sensor For example if the sensor has a 9 16 VDC power requirement a 12 V battery can be used to power both the sensor and the datalogger If the sensor has a 15 36 VDC power requirement a 24 V battery can be used to power both the sensor and the datalogger Input The same Super Puk can monitor a 0 5 V signal If it is ordered for use with a 4 20 mA loop an external resistor is included to convert the input to 0 5 V To measure a voltage signal simply remove the resistor Options A single analog output can be added
67. 485 modem 4 relays 10A 120VAC or 5A 250VAC Radiometric CS datalogger only 4 20mA RS232 SDI 12 3 relays 15A 125VAC bd Separate external temperature sensor required Advertised Greater of 0 2 cm or 0 196 target distance t 0 6 1 full span depends on range Greater of 1 cm or 0 4 of distance 0 25 full span 0 2 full span 0 25 full scale 0 05 full scale 0 25 full scale t 0 32 cm depends on depth Advertised Resolution o 0 045 cm depends on range 0 025 0 25 cm depends on range max 8 seconds 8 seconds 3 seconds max 0 1 1 seconds depends on sensor About 0 seconds 0 8 4 2 seconds minute minimum 30 second minimum Temperature EE 40 65 C w heater 25 52 C w heater 45 50 C 40 60 C 25 50 C 0 56 C 18 93 C ITRC Report No R 99 002 895 w temp sensor 615 w software 695 includes datalogger 1 560 w CR500 datalogger 1 200 w accuracy option 2 075 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf Table 7b Sensor specifications continued PT420 D Power Supply amp hr day Advertised Advertised Thermal Error 12 40 0 3 4 t 0 18 full VDC scale depends on range Intermountain Environmental Q oO o e n e Sensor Brand EE Sensor Model Automa
68. 7 AH sealed rechargeable battery external relay fiberglass enclosure and even a level sensor Intermountain Environmental 800 948 6236 sells all the components needed including small hand held HP terminals for communicating with the R2 A complete Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 level sensing and datalogging unit without the terminal costs about 1700 from Intermountain Environmental Power Two internal 9V cells operate the logger for 6 12 months An internal lithium battery allows for 10 year memory retention For use with 4 20 mA and other sensors a 12 VDC battery is also required The manufacturer estimates that a 7 AH battery will last at least 3 months An external relay controlled by the R2 switches power on to the sensor current loop only when a reading is being taken Options In addition to the accessories mentioned above other options for powering and mounting the R2 are available from Intermountain Environmental Global Water Datalogger 800 876 1172 http www globalw com Power Needs External Power Draw Number of Type of Accuracy Temp Logging Interval s Supply Battery amp hr day Analog Inputs Input Range 9V lithium N 0 0024 depends 1 0 4 0 2 full span Not 1 sec 1 hour 1 min battery on interval VDC includes sensor given w HRR option only Size Storage Resolution D
69. 88 amps The rated watts required equals 12 V x 2 88 A 36 watts An acceptable setup for this situation would be two panels each rated at 16 17 volts and 3 amps This would cost the user approximately 700 Standard PV array outputs are 14 5 16 and 17 1 V Two standard arrays with the same voltage output are required to charge a 24 V system A charge controller may be necessary to avoid overcharging the battery especially during the summer months Figure 25 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 PV Array Charge F Batte Fuse To DC Loads Control use E Figure 25 A simple solar electric system adapted from Real Goods 1993 Installation In the Northern Hemisphere face the panel in a southerly direction so that the sun s rays are perpendicular to the panel surface at noon The angle of the panel from vertical should approximately equal the latitude of the installation location Figure 26 If shade is allowed to cover any part of the panel during the power producing hours of the day output will be greatly reduced Shade on the solar cells acts like a sink drawing energy toward itself and away from the battery charger Real Goods 1993 A steel plate may be required on the underside to stop bullets Vertical spikes around the edge of the pane
70. 9 Proper installation of a stilling well with a flushout tube Desiccant General Chemicals that absorb water and humidity are called desiccants Many chemical desiccants have some sort of indicator to determine when they are saturated with water and need replacement Desiccant can come in a breathable pouch that will swell as water vapor is absorbed The most convenient form comes in the shape of small blue pellets or beads that turn pink and eventually white with increasing absorption This type should be replaced or replenished when it not longer contains any blue coloring Some types can be placed in a heated oven for several hours to evaporate off the absorbed water vapor and then reused Desiccant is often used to keep water out of electronics enclosures submersible pressure sensor vent tubes and bubbler tubes Itis either supplied in a plastic tube which all incoming air must flow through or as a pouch A desiccant pouch absorbs the surrounding air inside an enclosure and usually requires changing every 6 months in semi arid conditions 10 20 mesh indicating drierite desiccant can be purchased from W A Hammond Drierite Co at 937 376 2927 for about 8 per pound which is much cheaper than buying replacement desiccant from a sensor manufacturer Desiccant packs can also be bought in bulk A list of 20 companies that sell desiccant can be found at http www iscpubs com bg us prod prod1288 html Water Level Sensor and Datalo
71. B E J Palo o 88 5 88S E amp le 5 Z 3 e 2 a 4 a 8 2 sels A S 5 E sa mjgm S 2s 5 8 O 8 E E o7 a 7 a E E 2500L 9 8 9 10 Y 3 10 j Adjustable 10 8 5 7 10 8 Increasing the wave damping effect will decrease the water level response time 10 excellent 1 horrible Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period full scale 0 010 0 008 0 012 0 016 0 007 0 004 Max daily error during that 20 day period full scale 0 061 0 011 0 018 0 032 0 012 0 008 Advertised error full scale 0 027 at the tested range Primary advantages over other ultrasonic sensors Easy to use keypad and LCD display Penetrates foam Primary disadvantages over other ultrasonic sensors Special cable required High cost Bailey Fischer and Porter Ultrasonic 215 674 6000 http www ebpa com Power Supply Power Draw Output Advertised Advertised Lag Temp Cost amp hr day Accuracy Resolution Time Range 110 120 or AC only 4 20mA 2 relays 0 6 1 full span NA 8 25 52 C 1 900 220 240 VAC 0 3A 30VDC depends on range seconds w heater Price includes Sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General The Series 50US3000 Ultrasonic Flow Level Meter measures water levels and
72. C 1 sec 1 12x8x6 32 768 readings Instrumentation batteries interval sensor 2 current 5VDC plus 150 uV day Global Water WLI14 9V lithium battery 0 0024 including 0 4 VDC 0 2 full span Not given 1 sec 1 13x9x9 6 000 readings the sensor incl sensor hour cm Intermountain AquaPod Standard 9V battery N 0 0012 including 1 0 2 5V 0 5 full scale 25 50 C 0 5 sec 12x8x5 2 000 8 000 or 32 000 Environmental the sensor 24 hrs cm readings Intermountain Custom Solar panel and N 0 72 including the 1 Lundahl DCU 7110 0 3 full scale 25 50 C 1sec 30x30xl4 3 200 readings Environmental portable internal 12V battery sensor ultrasonic 1 day cm Stevens AxSys MPU 10 17 VDC Y 0 08 lor2 4 20mA raingauge 0 25 full 40 70 C lsec 17x13x13 60 000 readings digital and or serial scale 1 day cm 180 000 w data card Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 13b Datalogger specifications continued atalogger ommunications amp S H a H o En 50 9 s 8 c a Local Display Resolution Date Time Operations a ACR Systems OWL 500 8 bit 12 for SR Plus AGM Electronics Super Puk pool Badger Meter 2500 L 0 001 full scale Campbell Scientific CR10X 13 bit Campbell Scientific CR500 13 bit Coastal Environmental ZENO 3200 15 to 18 bits all but Systems 2 input channels Dr
73. CR10X but can still be a very difficult task depending on how complex the application is Customer support is very helpful and can prove invaluable to a first time Campbell user To physically install the CR510 mount inside a weatherproof enclosure the optional Campbell enclosure is good Place some desiccant and a humidity indicator inside along with the CR510 The 12V power supply battery also fits inside the optional enclosure Connect the 12 leads to the Power In terminal connectors on the CR510 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Follow the instructions for writing a ShortCut program in the Campbell Scientific CR10X Datalogger section of this report The steps are identical except for designating a CR510 instead of a CR10X in step 3 To configure the CR510 using PC200W software complete the following quick start steps This section only covers the steps necessary to configure the CR510 as a water level datalogger without any control or long distance communications abilities If using PC208W software refer to the Campbell Scientific CR10X Datalogger section of this report PC208W must be used if there is not a direct connection between the datalogger and the computer 1 Connect the CR510 to a computer using a RS 232 interface The SC32A requires a 9 pin to 25 pin computer serial cable Connect the 12 V leads to the Power In terminal con
74. Car Pro trending graph for the AquaPod ssssssuss 184 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Figure 69 AxSys MPU wiring schematic for a single 4 20 mA input The4 20 mA sensor must be able to handle 24V DG s d ttes feos heir vili Neue eg casmats 188 Table 1 Rechargeable battery sizing suggestions for a single 4 20 mA loop powered sensor Amp hour and weight data are for Power Sonic batteries 34 Table 2 Components for a sample battery powered compact setup ssse 35 Table 3 Components for a sample solar powered compact setup 36 Table 4 Stilling well dimensions for actively changing systems ssussss 43 Table 5 NEMA electrical enclosure ratings adapted from NEMA 1997 45 Table 6a Sensor evaluatiQns is e axe faga toig ep RUE RU ARTE ARTE EAER NR AEQ Re Mz nada 49 Table 6b Sensor evaluations continued essere 50 Table 7a Sensor specifications aee tcl case ta us ette ates e utopia tir auae at ede bep uo 51 Table 7b Sensor specifications continued uu o ecd petiti e tees eese DS 52 Table 8 Minimum installation distances from any wall for several ultrasonic beam angles EE A E T S 54 Table 9 Minimum stilling well diameters for several ultrasonic beam angles wall distance x 255 10 Obl oe dede doe tct date dele e dea
75. Contact the battery manufacturer before attempting this j 24V 100A 7 12V 200A nO C WO Cm o Q 12V 100A 12V 100A 12V 100A 12V 100A Battery Battery Battery Battery Series Parallel Figure 24 Series and parallel battery wiring schematics Parallel connections may be unsafe and are not normally advised Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 All parts of a system have electrical resistance including wires The voltage requirement of a device must be supplied at the device Amp hours To determine the approximate minimum battery amp hours AH needed determine the current draws of the sensor and any other devices powered by the battery This report specifies the average AH day for each device If a battery is used without a charger it usually only supply about 80 of the specified number of amp hours If a 100 AH battery is powering a device that draws 10 AH day the system will run for approximately 8 days before losing power A 100 AH battery cannot produce 100 amps for 1 hour and attempting this may cause battery damage or fires Typically battery manufacturers rate their storage not engine starting batteries at a 20 hour rate This means that a 100 AH storage battery could supply 5 A for 16 hours 100AH x 0 8 efficiency 5A x 16 hours A battery should hav
76. E B E 9 S pn mea Qc m 5b zo 52 9 g g g g A 2 e Om ggo lt D Q9 c Q S 55 a 5 no A a O ZENO 3200 2 2 3 1 10 N 8 5 10 excellent 1 horrible Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other dataloggers Seven 4 20 mA or fourteen 0 5 V inputs standard Six relays and several types of communications standard Adaptable to many uses 18 bit resolution Primary disadvantages over other dataloggers Very difficult to set up Large size Dryden Instrumentation Datalogger 907 344 4995 No web site Power Supply Needs External Power Draw amp Number of Type of Input Accuracy Temp Logging Battery hr day Analog Inputs Range Interval s 2 9V internal Y 0 0036 depends on 4 voltage or 2 0 10 mVDC 0 1 full scale 30 1 sec 1 batteries interval sensor current t00 5 VDC plus150guV 50 C day Size Storage Resolution Date Communi Relays Alarms Local Remote List Capacity Time cations Display Operations Price 12x8x6 32 768 13 bit Y RS 232 5V None N Y 795 cm readings External Bus excitation Price includes R2 datalogger R2 datalogger software General The R2 datalogger is a compact unit that can be used in many low power applications Normally the R2 is purchased along with a 12 VDC
77. E V Cebu ec n Du esae e ue su tu edite mete PE su Eat 25 Chapter 3 General Informotiott s ooo dec ras d Ea usi etra tone erga eee tu e cde ue ER de wee 27 Powel rn aoei dete Lea E ie ap Sada sat A E A a teeta ae eG 27 Sensor Output SIEDAlS oe ers vetadeaessesvigcusiegasizecavcss vat ysoceseecssses au eee ees in beteaweest 28 Data SIOFIPE n sca pem E Ate m M CNET LR M A LU EE 32 Calibration i oie etucuciteo arta oe i de a bon erba aad ce qr oa de Qs RUE 33 Low Power Applications c drea airport tetas ri dba etd buda do e d n idu 33 Batteries acoso obe cotes bam orc cce A erbe 36 Solar POWE pe ne eC e EC DA E E nIO 38 ROLiyS1 iiti Ies nn Basen snes bse Raadheed Lea ansats patetedesbds me bo n antan 40 Lightning Protections iosas yens tia n DERE p teet ME ae aede cbd neta 41 SGN EWE Sennen cH E 42 PICS CCAM aera oinen a e os toa e e a a d had O E bL tA 44 Electronic Enclosures esses nn e er D EX A GERI Y duet a E 45 15 DODT TEE e deste isdem ac easier Gi 46 SG RRA LY de 46 Sensor COMPAMSOMS sie oscasdiecig secti tate tuni eO ib dad cce ve da bec ee oe ocn 48 Chapter 4 Ultrasonic SensOrs oie echa eme rolesdva etri tec Re Da ula dud a iiai pi TIERE 53 OVENI e RR 53 Badger Meter RAS ONC se sei eter etu t t or Se E vce eatin ee Ree 60 Bailey Fiseher and Porter Ultrasonic s siss sccsssssessasiasnecaiantdsciorvediastaassnsueaesacesdadsiness 62 Campbell Scientific Ultrasonic x ice eerta tosis cach ic ide re e iion een 66 Endress Hauser DIECaSOTH
78. Ewg z 9 l J8 9 Aoc o o bi H o S c o 1 S 83 83 amp B S 32 z 4 8 6 2 o a a a c o S m WW f o a e B oO US Q g 9 9 S H A a E G FP10C 10 6 8 10 N Ji 10 Stilling Well 10 8 9 10 10 9 8 10 excellent 1 horrible Cumulative days Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Primary advantages over other float sensors Low power requirement Low cost Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf Primary disadvantages over other float sensors Voltage output only Affected by air temperature fluctuations ITRC Report No R 99 002 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 6 Submersible Pressure Sensors Overview General At any given level both liquids and gasses exert an equal pressure in all directions Water pressure increases linearly with depth of submergence For every 70 cm 2 31 ft of water pressure increases by 1 PSI The pressure difference between the atmosphere and the water around the sensor head produces a force on a flexible diaphragm Electronics convert the force on the diaphragm into a proportional electric signal All submersible pressure sensors studied had
79. Foam effects on ultrasonic water level sensors eeeee 57 Figure 36 Flowchart for selecting an ultrasonic sensor for a specific application 59 Figure 37 The improved response over other ultrasonic sensors of the Bailey Fischer amp Porter 50US3000 to fluctuating air temperatures sse 65 Figure 38 Response of Milltronics The Probe to changing water levels 74 Figure 39 Step response of The Probe at low currents due to capacitor charging close up of Eigute 38 ete tester ede xr eie edet eve tip tede des i re i ibtd 75 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Figure 40 Two basic float sensor models eee teet nene ennt nnne nnn 78 Figure 41 Flowchart for selecting a float sensor for a specific application 80 Figure 42 Response of the Intermountain Environmental FP10C to air temperature CAES d ose ee scettr eh auri audi dese RE M EE 85 Figure 43 Basic submersible pressure sensor layouts sse 87 Figure 44 Flowchart for selecting a submersible pressure sensor for a specific applicatigf d as roit a pad dades edo oss notat date mes Dod unn dst Mens 9 Figure 45 Response of the Automata LEVEL W ATCH 4 to water temperature PIANC HUAN TOTIS ood ben etait al mato e ee Coe oni cues ae ode E 94 Figure 46 Response of the Druc
80. G 11 94 cine decre ea o reete rit e epe a neben ene ded 67 Lu dahl CU rae ii Cases cec testo due Ca ca ates Merah cb itor 70 Milltronics Ultrasonic 5i dore peeled ete eere cee adn der mendes 73 Chapter gt Float SEnSOTS nu eet due na RE EE to avis A EEOAE SE AES cites 78 OOVEIVIe Wu E estie tS He t e E E EE AR RA 78 Celesc Floatation datos seque S e trauen dete debt Tax e end 80 Intermountain Environmental Float req dose RAM E geb reap be e de REA e Ro edu 83 Chapter 6 Submersible Pressure Sensors eee eee eeeee ee tenete sten n tane naut 87 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 DVT VIC Wo aus E OA MEME Geert onthe eh C DM LEE 87 Automata SUbmefstble ai doeet pete Ico Ret onte dele rena Nat E oue e o 92 Dr ck Submersible uneven rient UC ur Ne ona Ah eR Ya d PRI i 95 Global Water Submersible eo ife eerte d acce e os i y iae oap ee at 99 Instrumentation Northwest Submersible sessssseeeee 102 KPSI Submertsible iu enr eaedem re atii ere a ost ar lee aged 105 Stevens Submbetsible 2 seats tok ute rom I du it iss ANS D ertet ep NE RIPE TNR 108 Chapter 7 Bubbler Pressure Sensofs e ie p e eee ratas deb at reciben 111 OVOEVIGW qs ots a tes ade te cata mpl a Ne tbe Ree E 111 American Sigma BUD DIET sey ex esiti gt eda Ead Pe equ Maa tege ed 115 Campbell Scientific Bubble i poteat ite ure da
81. MA rating Power The system can be run off 12 VDC but draws a significant amount of current The compressor draws 5 A while running The recommended setting is a 4 second purge every 12 hours When the compressor is not running the sensor draws 0 5 A The transducer and the system are fused and extra fuses are provided on the circuit board Options For monitoring the water level in a well a concrete weight for the compression bell can be purchased for 400 If a display and manual purge button are not needed a pressure transmitter is available for only 1300 For corrosive or turbulent conditions different pressure bell sizes and materials are available Installation Mount the electronics enclosure up to 300 meters from the compression bell Mount the bell with stainless steel brackets or hose clamps and run the parflex tube through 4 schedule 40 PVC to the transmitter Read the warnings before installation Do not splice the tubing and do not remove the tube nut from the pressure bell fitting Loosen the tube nut to disconnect the tubing from the pressure bell Only finger tighten the tube nuts at the bell and at the transmitter Set the purge length and interval and the output freeze duration how long the sensor waits after a purge to begin reading again using the circuit board dip switches A 4 second purge every 12 hours is suggested To set the purge interval at 12 hours press down the 4 hour and 8 hour switches The LCD
82. N 8 9 10 excellent 1 horrible Primary advantages over other dataloggers Very easy to use Small size Low list price Primary disadvantages over other dataloggers Only one input No controls or long distance communications 8 bit resolution Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 ACR SmartReader Datalogger 800 663 7845 http www acrsystems com Power Supply Needs External Power Draw Number of Type of Input Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s Internal 3 6V 1AH Y 0 00018 7 8incl 25mA 200mV 2 5V 0 5 45 0 04 sec lithium battery temperature 5V and or 10V full scale 70 C 8 hrs Size Storage Capacity Resolution Date Communi Relays Alarms Local Remote List Price Time cations Display Operations 11x7x3 21 500 87 000 or 8 bit 12 for Y Cable None Flashing N Y 1 148 w cm 1 000 000 readings SR Plus LED Pager software Price includes SmartReader Plus 12 bit 7 channel 4 20 mA datalogger 839 for the SR and 989 for the SR w o software TrendReader software for Windows Interface cable General The ACR SmartReader has eight data channels including one for the internal temperature sensor A variety of DC inputs configurations for the 7 external inputs are avail
83. Palmtop PC G4 E on e g op a T C e Sun s o 9 5 ep 5 eu gt iz o0 489 4g SE org o S 3 D E 5 o S B g o z 2o o ge S a4 E S52 24 28 EE EBs s 2 chalma QE mj 5b ao 3 be 9 S E 5S 5 ag ae ae 2 lt 2 no al aq o Custom Portable 8 10 10 9 0 Not applicable Not tested 9 10 excellent 1 horrible Self contained recharging power supply Primary advantages over other dataloggers Small and portable Ready to log data straight from the factory Very easy to use Self contained recharging power supply Primary disadvantages over other dataloggers High price Must be mounted directly over the water Small memory Stevens Datalogger 800 452 5272 http www stevenswater com Power Needs External Power Draw Number of Type of Input Accuracy Temp Logging Supply Battery amp hr day Analog Inputs Range Interval s 10 17 Y 0 08 lor2 4 20mA rain gauge 0 25 40 1 sec VDC digital and or serial full scale 70 C 1 day Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Size Storage Capacity Resolution Date Communi Relays Alarms Local Remote List Price Time cations Display Operations 17x13x13 60 000 readings 10 bit Y 21 minute RS 232 2 10mA Relays Y Y 1175 w em 180 000 w data card logging interval 12VDC so
84. Sog 8 v5 we B5 BET 5 3 PozZ os 2E c EB a B o 9 9 S x g BES 9X Seg 9 E o E BS B S Z2P9OBISTS 3 a amp B9 mor 9 S ana me O 5 p 5b ceo 5952 g a g A oO o on 8 go lt 9 aot 7 e amp 9 Ae gt 6 AquaPod 10 10 10 10 Not applicable 6 10 10 excellent 1 horrible Attached sensor not taken into consideration Primary advantages over other dataloggers Ready to log data straight from the factory Only one standard 9 V battery required for a year of operation Very easy to use Primary disadvantages over other dataloggers Configured primarily for the I E float and pulley sensor Only one input possible Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Intermountain Environmental Custom Portable Datalogger 800 948 6236 http www inmtn com Power Supply Needs External Power Draw Number of Type of Input Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s Solar panel and N 0 72 including 1 Lundahl DCU 0 3 25 1 sec internal 12V battery the sensor 7110 ultrasonic full scale 50 C 1 day Size Storage Resolution Date Communi Relays Alarms Local Remote List Price Capacity Time cations Display Operations 30x30x14 3200 13 bit Y Cable None None N Y 3500 w sensor battery em readings solar panel datalogger Price inclu
85. Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Water Level Sensor and Datalogger Testing and Demonstration February 1998 Project on behalf of the USBR Mid Pacific Region by IRRIGATION TRAINING AND RESEARCH CENTER ITRC California Polytechnic State University Cal Poly San Luis Obispo CA 93407 Phone 805 756 2434 FAX 805 756 2433 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table of Contents Chapter 1 Background uda e eter cert ersten e ied ua spe edet a dos 6 Bougie n soe te o et tet pus veut ee ol os e M ade 6 UII co MR PT M 7 Chapter 2 Research Methodology ec tto eee ci de a ie a e e dieat 8 Testing STO ood a eie es lites Devo a oiu etia eere NA Tes eus hr ovS 8 Long term Trending aseessa eb petebat rake tes asd ci e Sel eaten 12 Air Temperature qd ML CUS ee oo e pe e e arte testes 14 Water Temperatute BHGCtS aeos tete abis o etae cod ipe habe da uda 16 Foam ETIGCIS ios dicite ton oet a dbi adeat tiv daban cei e e Gl edd 18 irre d st obediant ven adsit laudes date etasten e S Pec ba ncs 19 Wave Effects e eot tetendit cet utes Cd au dee odds oun uaa ambe cud de 20 Linearity and Hysteresis s eset dederat tu eds utut a etie dis SN Os 21 Drying PPC CUS a i e soi ves Lcd est ep Brigitte opui bolsa 23 Output Sa IY deem E 24 Datalogger ACOULA
86. a m H un A g 26 e w sE dD EA 5 z BZ 93 BE S H8 ao o 22 S E o 2523 35 a 25 eB EZ yg 5 c c E z TRZIN O amp D ob go S52 9 S ee eZ E Ao o On 226 lt o mb oW ue OQ c a pa no A Gs O Super Puk 2 2 3 1 N l 1 10 excellent 1 horrible Other Models The ICS is a PLC device with 8 analog inputs 8 analog outputs 32 digital inputs and 32 digital outputs Primary advantages over other dataloggers Low price Primary disadvantages over other dataloggers Ineffective instructions Software is not user friendly Small memory American Sigma Datalogger 800 635 4567 http www americansigma com Power Supply Needs External Power Draw Number of Type of Accuracy Temp Logging UM Bates lamin ane ioa imp Ranes re 12 VDC or Y 0 24 3 for water Sigma Depends 10 1 60 100 115 230 VAC level sensors onsensor 150 C min Size Storage Resolution Date Communi ML Alarms Local Remote List Price Capacity ume cations Pisay Operations mo 18 000 to 3 decimal RS 232 or culi to 4 Relays Pager About 4 000 116 000 places Modem 10A 120VAC Modem Report depends on readings or 5A 250V AC sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General The American Sigma 950 960 Flow Meters are designed to monitor water level and or flowrate at a single
87. able including seven 0 25 mA channels and seven 0 5 V channels This datalogger is almost as small as the OWL but is not watertight and does not have an optical data link All external inputs are wired into a terminal strip and data is transferred to and from a PC running TrendReader software via a plug in interface cable Power The SmartReader comes with an internal lithium battery that is guaranteed to last 10 years and is factory replaceable The datalogger however is only guaranteed for 3 years An external battery is required to power the 4 20 mA loop The external battery voltage must be within the specified input voltage range for the sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Input Five standard input ranges are available 0 25 mA for 4 20 mA sensors 0 200 mV 0 2 5 V 0 5 V and0 10 V Several combinations of input types are possible and the manual describes how to alter the input ports with resistors to accommodate non standard inputs Options The SmartReader has an 8 bit resolution and the SmartReader Plus gives 12 bit resolution 8 times better than the SmartReader for a higher price Three memory sizes are also available for the SmartReader The 32 KB model stores 21 500 readings the 128 KB model stores 87 000 readings and the 1 5 MB model stores 1 000 000 readings The seven standard input
88. ahl ultrasonic lost its echo because the foam absorbed its pulses and reflected them in many directions Other causes for a lost echo include extreme temperature fluctuations turbulence and occasions when water surface rises to within the blanking distance or beyond the maximum range While some sensors have an adjustable default reading that is output in the case of a lost echo others will either display only the maximum or minimum water level Most ultrasonic sensors will output the same default reading whether the water surface is below the minimum readable level or above the maximum readable level This means an automatic canal gate controller will respond incorrectly However this problem can be solved with a submergence shield which indicates when the transducer is underwater Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General Advantages Non contacting so are not affected by dirty water floating debris or aquatic wildlife Not affected by fluctuating water temperatures Not affected by high flow rates Easy to calibrate Low maintenance Excellent linearity and lack of significant hysteresis Can withstand freezing temperatures Long term reliability General Disadvantages Affected by air temperature fluctuations May reflect off floating foam or debris Must be aligned precisely May be affected by turbulent
89. al battery voltage must be within the specified input voltage range for the sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Input The OWL 500 reads 0 24 mA which is perfect for a 4 20 mA input The OWL 400 can read voltage inputs as small as 0 120 mV and as large at 0 38 4 VDC Using TrendReader software the user sets the desired voltage range Options There are five inputs available internal temperature external temperature electric current this is not a 0 24 mA logger DC voltage and 0 24 mA current Wiring 4 20 mA Voltage Voltage Transmitter Transducer Transducer Qo V IN COM SIG EX EX SIG SIG Brown DC Current Brown DC Voltage Brown DC Voltage OWL Hlack le oi Black 6 A Black OWL X Black OWL DC Power DC Power DC Power Source Source Source 4 20mA 3 wire voltage 4 wire voltage Figure 56 Three common OWL wiring schematics The DC power source must be within the voltage input range for the sensor Installation The logger can be easily mounted on a metal surface with its magnetic backing However it is recommended that the logger be securely mounted or placed on top of a horizontal metal surface A hole in the corne
90. al the plastic tubing around the metal with a hose clamp or piece of heavy duty wire to avoid leaks If a metal end piece is not supplied cut the submerged end at a 45 angle except for a captive air system Use as little tubing as needed and run it downhill the entire way from the electronics to the submerged end if possible This will help to keep water vapor condensation from accumulating in the line Mount the electronics above the high water line tubing can be run for long distances if required Since any plastic tubing can crack if exposed to the sun too long it should be run through PVC pipe or conduit in long term installations Test Results Results of all tests varied widely between bubbler types and manufacturers General Advantages Easy to install and calibrate Electronics can be installed away from the water Only inexpensive bubbler tubing contacts the water Not significantly affected by air or water temperature fluctuations Not significantly affected by drying Not affected by foam Not easily clogged by dirty water Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General Disadvantages May hang up debris Requires one of the following 1 A large nitrogen tank which must be periodically refilled 2 A power hungry air compressor with desiccant packs which must be periodically replaced High list price
91. als 8 25g SEIS E 2 B 3 Sls S ESlA QSIE E e qs 8 9 J 9 on s im a oe o g a T S iu E S812 S ES S e A g a 3 A Ri 2 16 S Sd on gt o D a a D Ds r 5 g 3 gt E E 2 o o s 8 H og a Q Pel 5 S6 1 gt S 2 5 amp EI S JIE z 4 9 amp 28 ed S B gm c o S m E d S e ae 9 Ez Q 5 B 5 S wo qe A n a E The Probe 9 9 9 10 Y 2 5 Adjustable 10 2 8 9 NA 8 Increasing the wave damping effect will decrease the water level response time 10 excellent 1 horrible NA not available Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Other Models For about 2545 Milltronics offers the OCM III an ultrasonic sensor with a datalogger and totalizer higher accuracy and faster response than The Probe 9 30 VDC is needed to run the OCM III Primary advantages over other ultrasonic sensors Very low power requirement Easy to install and calibrate Primary disadvantages over other ultrasonic sensors Output display can only be accessed with a screwdriver Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 5 Float Sensors Overview General There are two basic types of float sensor one which involves a pulley and counterweight and the other which utilizes a
92. and try to shake the battery Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 holder out Do not try to force the new battery in this can cause damage to the circuit board Data Analysis Data can be downloaded as a CSV file by entering 5 in EZLevel EZLevel does not have any data analysis capability Test Results Test results for the WL300 are described in the Global Water Submersible section of this report Extensive use of the WL14 slimline version in the field revealed that it is drastically affected by changing temperatures Figure 67 Due to the configuration of the sensor and datalogger datalogger accuracy could not be tested 0 6 Time days Figure 67 A daily WL14 cycle due to air temperature changes when not completely submerged The vertical gridlines designate midnight Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 d en S E SOn c a cc g E sae 5 5 8 BE 5 Eg gt E 5 Pos o s EH o S na D oY S ia E B9 g2 2 9 E 5g BEL 5 e88 82 los i 22 SE 2 5 58 8 Rg a S 228 lt 9 WL14 T 10 10 3 0 Not applicable Not tested T 10 excellent 1 horrible Attached sensor not taken into consideration Primary advantages over other dataloggers Low power requirement
93. anted against surge damage when lightning protection is ordered Excellent linearity and hysteresis Primary disadvantages over other submersible pressure sensors High price with required lighting protection 335 extra May be easily damaged without lightning protection Stevens Submersible 800 452 5272 http www stevenswater com Power Power Draw Output Advertised Advertised Advertised Lag Overpressure Temp Cost Supply amp hr day Accuracy Thermal Error Resolution Time Rating Range 12 5 35 0 3 4 20mA 0 25 0 1 full Infinite None 2x 1 50 C 707 w 6 VDC full span scale C m cable Price includes Sensor 6mofcable General The Submersible Depth Transmitter II SDT II is housed in PVC as opposed to most other sensors which are housed in stainless steel or another metal A wire termination enclosure is attached to the free end of the cable The enclosure protects the cable breather tube and vents it to the atmosphere through a small hole While it is inconvenient during installation the termination enclosure allows any 2 conductor shielded wire to be run to the datalogger Power The SDT II cannot be run off a 12 VDC power source since 12 5 35 VDC are required A diode which provides reverse polarity protection raises the voltage requirement to 12 5 V minimum The output is 4 20 mA The manufacturer can install Water Level Sensor and Datalogger Testing and De
94. any additional capabilities Data can be graphed and printed from the DOS program Figure 61 In addition to reporting sample data the software can display program settings and event logs saved by the 950 960 Data can be averaged over an adjustable interval The database functions allow many data files to be consolidated into a single database All Insight software functions and 950 960 programming can also be accomplished over a modem Alarms can activate relays dial a PC over a modem and give an alarm report or dial a pager Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Site Id 76794800 File name 11241452 00L Level icn Graph amp pan 12 hnur amp EBH Level 150 00 450 00 155 00 455 00 120 00 420 06 105 00 105 00 50 00 50 00 75 00 60 00 amp n nn 45 00 45 00 50 00 nc 15 00 i5 o0 0 00 3 16 00 Hed 20 00 Wed 22 00 Hed 00 00 Thure 02 00 Thure O4 00 Thure Dg 00 Thure Nov ii Nov 1i Nov ii Nov 12 Nov i2 Nov 12 Nov 12 SE SE SE SE SE SE SE Figure 61 An Insight trending graph for the 950 906 Test Results Even though the Insight software uses a DOS interface similar to Windows it can be a bit difficult to understand initially There are many programming data analysis and communications options that must be configured Due to the configuration of the datalogger and sensors datalogger accuracy could not be tested
95. ars the potentiometer should be replaced 20 While surge protection is not provided it does not seem to be a problem A large surge would only damage the potentiometer Test Results Test results came out relatively well Hysteresis was about average and the linearity was excellent Waves since a stilling well is required and water temperature did not affect the sensor Due to at least two factors extreme air temperature fluctuations did adversely affect the output Figure 42 First a change in temperature changes the resistance of electronic parts and the FP10C translates water level into a resistance Second the metal pulley and beaded cable will expand with increasing temperature Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 1 00 4 70 o 0 95 50 6 co 5 i a J 8 5 S 4 T 2 wl en x B 0 90 agii we ao 0 85 r r r r r 10 0 10 20 30 40 50 60 Time hours Sensor Air Temperature Figure 42 Response of the Intermountain Environmental FP10C to air temperature changes e 6 o 5 5 g un A amp l rz e NS E a7 5 D g Ogles B9 8 m Q o gt E a sale 8 Jal BE S g z 2 3 8 28 2 z Egla 38 RB 8 B BE B 8 3 O83 8 a BS S Bs s g A ue ee Ve lgble S S38 S amp A B js js I lg que pele 3 J v a
96. as a range 12 to 24 VDC or a specific voltage 12 VDC For specific voltage requirements a regulated power supply is usually needed DC powered devices are preferred over AC powered devices at remote sites AC to DC and DC to AC conversions are possible The rate of energy consumption is defined as volts V x amps A called watts W The total power consumed is computed as Power Volts x Amps x Hours Watt hours 1 A kilowatt is 1 000 watts so 1 kilowatt hour 1 000 watt hours Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 In a water level measurement system the datalogger sensor output and sometimes the sensor unit all require separate power Every DC electrical device requires a certain excitation or voltage drop across the device contacts Each sensor and datalogger also has a certain current draw which is rated in amp hours AH f Adt Batteries are rated for volts and amp hours storage capacity and each must be considered carefully Battery amp hour ratings do not correspond with their power capabilities For example a 1 AH battery cannot supply 1 amp for 1 hour Watts volts x amps Electrical devices require a certain voltage Electrical devices require an average number of amps per hour amp hours Sensor Output Signals General Sensors have two basic output signal ty
97. ate Communi Relays Alarms Local Remote List Price Capacity Time cations Display Operations 13x9x9 cm 6000 12 bit Y Cable None None N N 795 w sensor smaller optional readings software Price includes WLIA datalogger and submersible sensor Interface cable EZLevel software General The WL14 includes a datalogger and the WL300 submersible water level sensor see Global Water Submersible The entire setup can run off one standard 9 V battery EZLevel software and an interface cable can only be used to download data at Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 the site A slimline option allows the sensor to be easily hidden inside a 2 inch well or PVC pipe Power The WL14 comes with a 9 VDC lithium battery installed which should last for a year A standard 9 V alkaline battery will last about 6 months Options Available sensor ranges are 3 14 28 60 120 and 250 feet If more than 25 feet of cable is required specify this when ordering 1 25 ft The high recording rate HRR option allows 1 2 5 and 10 second recording intervals in addition to the standard 1 to 60 minute intervals The logger can also be purchased separate from the sensor for logging 4 20 mA and 0 4 V analog signals The slimline enclosure option allows the logger to sit inside a 2 inch well or PVC pipe while a rim
98. aw Output Advertised Advertised Advertised Lag Overpressure Temp Cost Supply amp hr day Accuracy Thermal Error Resolution Time Rating Range 11 13 0 3 4 20mA 0 0 5 0 0196 of Infinite None 3x 40 328 w 6m VDC 5V 0 1mA span year span C 125 C cable desiccant or 0 20mA replacement Price includes Sensor 6mof vented cable Desiccant replacement General The Automata LEVEL WATCH is housed in a PVC tube with plastic caps sealed to the ends with epoxy The water inlet holes are located in the upper cap to keep air bubbles from being trapped inside the sensor A filter keeps large particles out but the sensor is susceptible to plugging by silt and other fine particles because dirt settles on the bottom of the chamber Since water enters from the top of the sensor the LEVEL WATCH should not be used when shallow water levels must be measured The water that remains inside the sensor will give a false water level reading and will damage the sensor if it freezes The user must either supply a desiccated box at the end of the cable or buy a desiccant replacement The desiccant replacement is an air bladder that allows the vent tube to equilibrate to barometric pressure while keeping moisture out of the sensor Less maintenance may be needed than with a chemical desiccant but the air bladder may adversely affect the output under fluctuating air temperatures Power Supply 12 VDC 10 to the se
99. ble Sigma offers a solar battery charger While an 18 000 data point memory is standard for both models up to a 116 00 data point memory is available An alarm relay cable assembly must be purchased in order to utilize the alarm relays For measuring flows three different totalizers are available The available level flow sensors available are bubbler submerged pressure ultrasonic velocity and submerged area velocity Other compatible sensors include pH ORP temperature dissolved oxygen Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 conductivity and rainfall meters Up to two 4 20 mA outputs when using AC power only four alarm relays and RS 232 or modem communications are available The 950 960 can be mounted with four bolts to any structure or the user can purchase a wall bracket suspension harness or manhole rung hanger from American Sigma The following options are recommended Extended memory Rechargeable gel battery or AC power backup Wiring American Sigma sensors simply must be plugged into the correct input jacks on the side of the 950 960 Installation The Sigma 950 is completely sealed even with the door open so wall mount it where convenient To set the datalogger for use with the bubbler go through the following quick start steps The steps for any other sensor type are very similar After adjusting
100. cale Max daily error during that 20 day period full scale Advertised error full scale The high errors in this table are due to a leak in the pressure bell Primary advantages over other bubbler sensors Operational without the compressor for up to 30 days No lag time Primary disadvantages over other bubbler sensors High current draw Susceptible to leaks Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 8 Dataloggers Overview General Dataloggers store water level sensor output data or other electrical output data in electronic memory There are two main types of dataloggers available the first of which simply records data which can be later transferred to a laptop computer or other hand held unit The second basic type of datalogger is capable of long distance 2 way communications and may also have control capabilities All dataloggers require specialized software for downloading and analyzing the recorded data Power Smaller dataloggers have their own internal battery but will usually not power the sensor output loop The more complex dataloggers require a DC power source usually 12 VDC but will power one or more sensor output loops 4 20mA RT Datalogge Datalogge External Mat ee Power
101. convert a 0 100 mV signal to 4 20 mA If only a 42 inch ID stilling well is available see the section on other models below Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 The following options are recommended Sensor termination enclosure Polyurethane vented cable Lightning arrestor Installation Place the sensor tip slightly below the lowest water level that is of interest to monitor Secure the cable to avoid changes in the sensor placement If possible hang the cable with the yellow fibrous Kevlar cord Maintenance The construction of the Druck submersible sensors allows for several helpful cleaning options If the inlet holes at the tip of the sensor clog a wire brush can be used for cleaning The black nose cap is removable but no objects should be put inside the end of the sensor when the cap is removed If mineral deposits build up remove the cap and soak the unit in CLR normally used to clean coffee makers Do not try this on other sensor makes without first contacting the manufacturer Additionally the nose cap can be filled with silicon grease to stop mineral growth This will stop water from entering the nose cap but transmits pressure to the diaphragm Test Results Overall the Druck PTX 1830 performed well among the submersible pressure transducer Especially impressive was the relatively high accuracy duri
102. d think the canal is empty when in reality it could be full The sensor also lost the echo when 10 cm waves were created on the water surface and during high air temperatures On the positive side the sensor had good linearity acceptable hysteresis and long term reliability E 5 B 9 8 8 5g 8 88 s o lE e Ez E o T Eal oN n D Eai D 5 fe 9228 8 gals 2FIS 2 8 12 3 3 Is J E Su 5 EelA Ass ES a 8 S s E o on S slo ghjg S A T E o E c 3 O23 S Ps 9 82 5 A d a e 29 S Sud E olg gt gt Z amp E 8 p Belo o Salix ogg S El 5 1 gt 5 A n s S 2 c8 A G e s en o S s gms 9 Sm E E a eg D Q 3 S 9 3 m a H O 3 w E z DCU 7110 10 8 9 10 N 1 1 1 10 7 8 7 10 7 10 excellent 1 horrible Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period full scale Max daily error during that 20 day period full scale Advertised error full scale Maintenance No maintenance is necessary for the DCU 7110 except for keeping the area underneath the sensor clear of obstructions The sensor housing is sealed to moisture but is not waterproof Other Models If a longer range than 4 9 m is needed the Lundahl DCU 1103 has a 0 6 15 m operating range Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Repo
103. day period full scale Max daily error during that 20 day period full scale Advertised error full scale Other Models Also available from Stevens is the Ultrasonic Level Transmitter ULT a programmable 4 20 mA output device with a 0 3 3 m range For use with the Stevens AxSys MPU datalogger order the SDI 12 submersible pressure transducer Primary advantages over other submersible pressure sensors Long term reliability PVC housing can survive in harsh environments Primary disadvantages over other submersible pressure sensors Atleast 12 5 VDC power source required Additional supplies needed for dropping down a stilling well Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 7 Bubbler Pressure Sensors Overview General Bubblers measure water level by sensing the pressure of one or more air filled tubes or chambers that have an open submerged bottom end The higher the water level and therefore the higher the static pressure at the end of the bubbler tube the more air pressure is needed to fill the tube Air is often continually bled out of each tube for three reasons 1 to keep dirt and debris out of the line 2 to lower the effect of a leak and 3 to keep the air in the tube from dissolving in the water The pressure in the tube minus atmospheric pressure
104. des Lundahl DCU 7110 ultrasonic sensor Dryden Instrumentation R2 datalogger 12 V rechargeable battery Solar panel Ammo box enclosure Datalogger software Interface cable General This custom made portable system is an ultrasonic sensor datalogger and power source contained in an ammunition box After deciding on which components to include Imperial Irrigation District commissioned Intermountain Environmental to build the unit When inquiring about the unit one must ask about the custom portable head gate monitoring system originally made for Imperial Irrigation District The R2 datalogger is discussed in the Dryden Instrumentation Datalogger section of this report The Lundahl DCU 7110 is discussed in the chapter on ultrasonic sensors The unit must be specially ordered from Intermountain Environmental but proves to be very convenient If the exact configuration specified by Imperial Irrigation District is not used the price could be lowered by as much as 1000 per unit Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Installation Secure the monitoring system over the water so that the bubble in the bulls eye level is centered The R2 Datalogger operator s manual provides good instructions on how to interface with the unit using a direct connection to a PC or laptop CrossTalk or Procomm or a Hewlett Packard
105. desiccant when the bag is swelled to twice its normal thickness Since this is difficult to determine it is recommended that a color changing desiccant pack be used instead of the standard desiccant supplied by the manufacturer if possible If the transmitter pressure sensing face needs cleaning gently wash it under a faucet Test Results Among the submersible pressure transducers testing the SDT II had average linearity long term reliability and hysteresis It performed below average Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 during water temperature fluctuations No maintenance was needed throughout the testing period us en on GH S g amp o I2 e A 3 Es m E o s o o 2 e amp 618 eels e 8 og RE 2 S z E 25 88 z o o Bo E e gels Bele E8 258 p 8 8 I E E 8 8 z o een lic Sia PS Pele amp B TER I IS I E So2 8 s B8 8 8 amp 8 i T S a 9 m4 Bz D H 9 C8 48 Eo BRIS 8 s eA m 2 A 3 g ilo mx e 8 ee la 8 le l E S pele z goelen e fe z 2 gt 3 39 B 8 B3aj i8 3 i g 6 B B J amp 3 s e l ES E Jg 3 o S3 E E 5 5 B 4 in a m Bl g he 52 a o 2 S 5 5 e O e e SDT 10 7 10 N 10 5 10 10 8 9 NA 9 8 8 10 excellent 1 horrible NA not available Cumulative days Avg daily error during that 20
106. drywall heater which fans air through a propane flame and give off 150 000 BTU hour was set up to blow heated air under the canvas enclosure Radiant heat effects were virtually eliminated by forcing the heated air to flow around a plywood board No sensors or electronics were in a direct line of sight with the propane flame Air temperatures inside the tank were recorded with 3 thermocouples Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 s es an ae SS cur 4 a ei ur Figure 10 Test Tank Covered with a Canvas Tarp for Air Temperature Testing Testing Sensor outputs and temperatures were logged once per minute to a CSV file On the first day the air temperature in the tank was raised to approximately 55 65 C and maintained for 2 hours The enclosure was allowed to cool to ambient temperature 30 C for 2 hours and then heated again for 2 hours Overnight the temperature dropped to 13 C On the second day of testing the air temperature was maintained at 55 65 C for 6 consecutive hours Data Analysis Figure 11 is a sample response in sensor output to air temperature fluctuations The air temperature and the water level sensor output were plotted on the same graph but have different axis Sharp changes in sensor output during a rapid air temperature change as seen in Figure 11 were a common result Water Level Sensor and Datalogger
107. e the electronics must be the same temperature as the ambient air which may take some time if the air temperature fluctuates rapidly Radiant heat can affect the electronics so ultrasonic sensors should be kept in the shade However the air in unventilated stilling wells may heat significantly during the daytime producing large air temperature fluctuations Figure 33 displays typical ultrasonic output fluctuations due to extreme temperature fluctuations as measured at ITRC 1 00 Lad i 1DU E 70 DEN f 0 85 r r 10 0 10 20 30 40 50 60 Time hours Sensor Air Temperature o a Sensor Output meters Air Temperature C o o Figure 33 A typical output response of an ultrasonic sensor to air temperature fluctuations Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Turbulence In turbulent areas a stilling well may be required in order to maintain a flat reflective water surface In Figure 34 one can see how well several ultrasonic sensors read the water level without a stilling well when relatively small waves were present on the surface Endress Hauser Milltronics and Badger Meter use signal dampening to help avoid noise due to waves or interfering acoustics The operation of each individual sensor will be discussed in further detail in later sections 60 50 AR eo I
108. e 30 T 1 steel will stop most bullets from harming the equipment Bland colors also help to deter bullets by not attracting the shooters Do not use a fan to bring external air into the NEMA 4 enclosure which will bring in dust A vent is required to let off hydrogen gas from the battery unless a sealed battery is used but not for the electronics Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 p T 2 5 Lock I 2 Vent holes za T 1 Steel Z Batteries L Figure 30 Basic sensor electronics enclosure ISO 9001 Definition Some manufacturers advertise their ISO 9001 certification but exactly what this means is difficult to determine Mitra 1998 states that the ISO 9001 standard specifies quality system requirements for use when a contract between two parties requires the demonstration of a vendor s capability to design and supply the product or service Basically it attempts to certify quality assurance at all stages from design to servicing Mitra 1998 Terminology The following terms are commonly used in describing sensor and datalogger characteristics and performance Accuracy ratio of the error to the full scale output or the ratio of the error to the output as specified expressed in percent ASTM 1995 Error algebraic difference between the indicated value and the true val
109. e date and time are not affected by a loss of external power 4 20 mA readings were within 0 196 full range of the actual current o on S ob ZS Ovn a g amp a Gc S S25 3 88 leg SE SER gm 5 o Ep oz os gt z g og n D o g e S ez SEO o amp o D o amp e 8 gk 5 i 232 23 ISE 3g 8 535 8 z chnm QO amp m 55 zo Ss be 2 5 Bad A oO e orn 2go p S8 r SRA no a o AxSys MPU 7 9 6 3 N 10 8 10 excellent 1 horrible Primary advantages over other dataloggers Local display and front panel keypad Ability to transfer data on a data card requires a card reader but not a laptop NEMA 4 enclosure Primary disadvantages over other dataloggers DOS based software is difficult to use Sensor must be able to handle 24 VDC input Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 9 References Lehmkuhl M 1998 Introduction to SCADA Irrigation Training and Research Center California Polytechnic State University San Luis Obispo CA Miller M 1998 Precautions for Underwater Instruments Water Environment and Technology April 1998 42 44 Mitra A 1998 Fundamentals of Quality Control and Improvement Prentice Hall Upper Saddle River NJ NEMA 1997 Enclosures for Electrical Equipment 1000 Volts Maximum Standards Publication 250
110. e enough capacity to last between 4 and 21 days without recharging to ensure the proper rate of discharge If batteries of the same size capacity and age are placed in parallel their amp hours are additive Real Goods 1993 Batteries normally can only supply 80 of their rated AH Storage batteries are typically rated for a 20 hour minimum discharge Types The two most common types of storage batteries are lead acid and nickel cadmium Nicad A car battery is a type of lead acid battery but should not be used for remote sites They are designed to only ever lose about 10 of their charge Lead acid batteries Must be vented to avoid the accumulation of explosive hydrogen gas Should never be exposed to temperatures below 10 C Quickly lose their storage capacity after a certain amount of usage May only be hooked up with batteries of the same size capacity and age May need refilling with distilled water A lack of water indicates the need for a charge controller or voltage regulator Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Nicad batteries Are very expensive Canbelong lived if only cycled at about 3096 capacity so that at the battery always holds at least 7096 of its charge Have a constant voltage until the last 10 of capacity Can be mixed with different types of Nicad batteries but not
111. e modules solar panels communications hardware and many other devices To interface the datalogger with an RS 232 computer port the user must purchase an RS 232 interface cable SC929 85 or an optically isolated RS 232 interface SC32A 145 The SC929 is only suitable for short term connections such as to a laptop computer A fiberglass reinforced enclosure costs 190 and should be used with a humidity card and desiccant packs External surge protection is available but is only recommended for high risk applications PC208W software must be purchased for most uses but PC200W software is sufficient for direct connection between a computer and the CR10X PC200W and ShortCut a user friendly program builder are free and can be download from http www campbellsci com resource html or ordered from Campbell Scientific The following options are recommended 2V power supply with charging regulator and rechargeable battery Terminal Input Modules if logging 4 20 mA or 0 5 V sensors Enclosure Desiccant packs and humidity indicators ShortCut software free PC200W software free if connecting directly to a computer SC929 laptop or SC32A and 9 pin to 25 pin cable permanent connection RS 232 interface if connecting directly to a computer Water Level Sensor and Datalogger Testing and Demonstration
112. ection should be supplied at the data acquisition end Options The PTX 1230 is rated at 0 25 full scale accuracy and costs 595 695 while the PTX 1830 is rated at 0 196 full scale accuracy and costs 875 995 depending on the measurement range Ranges from 0 7 to 630 m are available with increasingly higher prices at ranges less than 5 PSIG 3 5 m Druck does not supply desiccant tubes for use at the end of the vent tube stating that a dry wire termination enclosure is more effective If a dry enclosure is not already available the STE 110 Sensor Termination Enclosure is available for 190 The STE 110 s NEMA 4 enclosure comes with reusable color changing desiccant packs to keep the inside air dry The breather port which allows the enclosure to equilibrate with barometric pressure is covered with Gore Tex to keep water drops out This feature actually makes the STE 110 and therefore the end of the sensor cable submersible which is not possible with any of the other submersible pressure sensors that were reviewed The STE 110 will keep not only the vent tube but also the entire cable free of water Tefzel cable is available instead of polyurethane but is much more expensive and is not needed for typical irrigation applications Different lightning arrestor units are available for 4 20 mA 1 5 V and 0 100 mV sensors The SCU 220 Sensor Conditioning Unit allows the user to adjust the zero and span remotely and can be used to
113. ecurely connect the plastic bubbler tube to the metal tube provided Place the end with the 90 angle piece just below the lowest water level that is of interest to monitor Fasten the metal tube to a fixed support using plastic ties or hose clamps Connect the necessary electrical wires to the 24 position detachable terminal strip as specified in the manual Unless only a 2 full scale accuracy is required or the water level is known to change slowly set the sample time at 30 seconds If the span will not reach exactly 00 00 inches during calibration get it as close as possible and continue the calibration A staff gauge or measuring tape is needed to determine the exact depth Maintenance Periodically check the calibration and remove any debris that has hung up on the bubbler line No desiccant is needed Test Results The Digital 12259 displayed significant lag time compared to most other sensors even at the minimum sample time setting Figure 52 The sensor did perform well during fluctuating air and water temperatures and had excellent long term reliability Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 120 e 100 Adjusted Sensor Output cm 90 0 10 20 30 40 50 60 70 Time minutes Actual Water Level Digital Output Figure 52 Response of the Digital BLM to water level changes sample time
114. ed measurement process and any SDI 12 sensor Many of these sensors are designed specifically for Campbell Scientific dataloggers and are not compatible with many other datalogger brands The CR10X can also monitor a simple 0 2 5 V analog signal such as a potentiometer To monitor a 4 20 mA sensor the user must purchase a Current Shunt Module CURS100 35 or a high precision 0 01 tolerance 10 ppm C 1 4 Watt 100 Q resistor to convert the signal to 0 2 5 V Either a 2 1 Voltage Divider Module VDIV2 1 35 or a network of external precision resistors must be used to monitor a 0 5 V signal Options The standard CR10X comes with a wiring panel and 128K memory 62 000 readings Extended memory can be ordered for holding up to 500 000 or 1 000 000 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 readings The operating temperature range can be extended from 25 50 C to 55 80 C The following external items are also compatible with the CR10X keyboard display reference thermistor 12 V alkaline battery 12 V power supply with charging regulator and rechargeable battery and wall charger Terminal Input Modules 35 for 4 20 mA up to 50 V or bridge input signals must be ordered for these types of sensors Campbell Scientific also manufactures multiplexers synchronous devices relay drivers extra data storag
115. ee points can be used as long as they are precisely measured and cover most of the sensor span Write down an averaged real time reading for each Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 e Plot the three points and draw a linear best fit curve through them and determine the y intercept and slope Figure 66 is an example where the slope is 0 0224 and the y intercept is 0 5004 90 80 70 60 y 0 0224x 0 5004 50 4 40 30 Actual Depth cm 0 500 1000 1500 2000 2500 3000 3500 4000 Averaged Real time Sensor Output Figure 66 Linear calibration curve fit for the WL14 f Enter the slope and the opposite of the y intercept into the sensor with EZLevel 11 The WL14 is calibrated to output the depth of the pressure sensing element The user may want to offset the data so that is reads an actual depth or the head over a weir To enter an offset take an average real time reading from the datalogger Subtract this reading from the actual depth or head Add the result to the existing y intercept value item 8 in EZLevel Enter this as the new y intercept New y intercept Actual depth or head Datalogger output Factory y intercept 12 Maintenance The 9 V battery is very difficult to replace in the slimline version Unscrew the top of the datalogger hold it upside down
116. el Identification such as Badger Meter Ultrasonic which will identify the sensor 10 Click on the Setup tab 11 Enter a Geo Description such as Weir 1 to identify the location 12 Enter a Main Recording Interval in minutes 13 Click Send to send the new settings to the datalogger Click OK when the data loss warning box appears 14 To download data choose Download Data from the Communicate menu Click Convert to ascii file followed by All Data or Since last download The 2500 ultrasonic sensor can also be configured with Flars Under the Communicate menu choose Digital Channel A picture of the 2500 front panel will come up Click on Digital 1 or Digital 2 if applicable If a connection is made with the datalogger the simulated LCD screen will display the same thing as the actual 2500 LCD screen Adjustments can be made by clicking on the simulated keypad This process takes more time than making adjustments at the site Maintenance No special maintenance is required Data Analysis Data can be downloaded as a tab separated variable file TSV which can be opened by Excel and other spreadsheet programs Flars for Windows also has a Data Manager under the Data menu Data can be printed in a graph Figure 62 or a table format and can be appended to an already existing database Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Badger M
117. em a sacrificial anode is available as a low cost alternative to titanium housing Order either the mounting clamp or the cable hanger to ease installation Finally a cable splicing kit and a junction box are optional The following options are recommended Lightning protection kit 4 20mA output Open faced nose cap Desiccant Polyurethane jacketed vented cable Series 200S 720 0 25 static accuracy or Series 210S 730 0 1 static accuracy Cable hanger Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Installation Place the sensor tip slightly below the lowest water level that is of interest to monitor Secure the cable to avoid changes in the sensor placement Maintenance Replace desiccant and clean the removable nose cap with a brush as needed Test Results The KPSI Series 210S performed very well among the submersible pressure sensors Only the Druck PTX 1830 achieved a better score on the water temperature test The 210S got a low long term reliability score because it was the only sensor to be damaged by an electrical surge during testing If the lightning protection option had been included this most likely would not have happened The standard circuit design has now been upgraded and improved to make the unit more tolerant of surges The KPSI submersible had excellent linearity and hysteresis ke o
118. ement Programming Controls and Telemetry DC Power 458 w software ACR Systems OWL 500 p ACR Systems SmartReader Plus 7 AGM Electronics Super Puk Rae eee gt NE id i i m id i Campbell Scientific CR500 1 2 1 1 7 N 10 CR510 Coastal Environmental ZENO 3200 2 2 Systems p ibi 7 Intermountain AquaPod 10 10 Environmental Intermountain Custom 10 NT Environmental portable Mo REFERS EAT i 10 excellent 1 horrible NA not applicable NT not tested Attached sensor not taken into consideration Requires one standard 9V battery for both the datalogger and the attached sensor Self contained recharging power supply 1 148 w software 425 w software About 4 000 depends on sensor 2 425 w sensor software 1 410 w PC208W cable 5 760 w software cable A 1 320 w software 795 w sensor software 714 835 w software 10 depends on mem range 3500 w sensor battery solar panel datalogger 1175 w software 134 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 13a Datalogger specifications Datalogger Model Type of Input Storage Capacity per day Number of Analog en ues Logging Interval s Power Supply Needs External B Power Draw A hr Datalogger Brand 0 ACR Systems OWL 500 Internal 3 6V 1AH 00018 0 24mA 0 120 mV 1 full scale 40
119. ensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 in series into the array visible on any solar panel The most common array consists of 36 cells connected in series that produce a standard output of 16 to 17 volts Another common output is 14 5 V These voltages are excellent for charging a 12 V battery and allow for the small voltage fade inherent in PV operation If a 24 V system is being used two PV modules with the same voltage output can be connected in series PV modules are rated for volts and amps or watts which equals V x A First determine whether a 12 V or 24 V system will be used Second determine the AH day required The hours of usable sun per day must be taken into account which varies from about 6 0 to 3 5 across the continental United States The array should be oversized by 15 to account for inherent power losses due to temperature dirty panels and module inefficiency Real Goods 1993 The following equation will estimate the total PV module amp rating required System AH day Hours of usable sunlight per day Total PV amp rating needed x1 15 7 As an example consider a system that requires a 14 30 VDC excitation and draws 10 AH day It will be installed in San Luis Obispo CA which receives approximately 4 hours of usable sun per day during the winter The total PV amp rating needed is 10 AH day x 1 15 4 hours of sun 2
120. ent Terminal list choose IBMPC Click OK Procomm Plus is now configured 12 Apply power to the ZENO If the power was already on disconnect and reconnect it After about 5 seconds a message should appear on the screen If this does not happen the datalogger does not have power it is not connected to the computer or the terminal emulation software is not configured correctly 13 Type U and press Enter to access the User Menu Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 14 15 16 17 18 19 20 21 22 23 24 25 26 From the User Menu enter F then S to set the date and time Note that the date is in the format YY MM DD February 1 1998 would be entered 98 02 01 Time is in the format HH MM SS Return to the System Functions Menu and enter C3 2 if data should be dumped as a CSV file Enter U to return to the User Menu Enter S to access the Sample Period Menu Set the sample interval duration and time offset Refer to the manual under Changing the Data Collection Schedule for more information Return to the User Menu and enter Z to access the ZENO Program Menu When prompted for a password enter ZENO To eliminate the password enter W then A When prompted for the new password simply press Enter To ease configuration it may help to delete all existing Sensor Menu Processing Menu and Data Output M
121. enu records From the ZENO Program Menu access the Sensor Menu In Record 1 change the settings to those listed in Appendix D under 4 20 mA Current Loop or Sensors with 0 12 VDC or 12 12 VDC Analog Output for a 4 20 mA or0 5 V sensor respectively The second column under Sensor Menu lists the appropriate values and the third column lists the commands for entering those values Add a new sensor record for each sensor Specify a distinct Sensor Name and Sensor Input Channel for each sensor From the Program Menu access the Processing Menu Add a new Process Record for each sensor following the settings in Appendix D The first number in the Sensor Input Channel the 2 in S2 1 for a 4 20 mA sensor or the 2 in S2 for a 0 5 V sensor must equal the Sensor Record number for that sensor For basic sensor operation enter a 1 for the second number if required From the Program Menu access the Data Output Menu Designate Record 1 as a time stamp Enter 3 for Item 1 Add a new Data Output Record for each sensor following the settings in Appendix D The first number in the Data Process Record must equal the Process Record number for that sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 27 A final Data Output Record is often added so that each new data reading is displayed as a new line on the terminal screen Set the Field
122. er Conservation Office of the Mid Pacific Region of the USBR contracted with the Cal Poly ITRC to conduct a study on water level sensors and to produce this report Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 2 Research Methodology Testing Site General Seventeen water level sensors were mounted inside the concrete volumetric tank test tank at the Water Delivery Facility of the ITRC see Figures 1 2 and 3 Electronic enclosures and any other peripheral sensor equipment were mounted on the outside wall of the test tank Figure 4 All sensors that were not strictly loop powered power and data run through the same wire loop were wired to a single power distribution box that provides 110 VAC and 12 VDC power from the central Remote Terminal Unit RTU panel Figure 1 The Water Delivery Facility volumetric tank test tank used for water level sensor testing Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 ma il Oleg fete al Ultr rgsonics 3w RLW Floats and Bubblers Figure 2 Inside view of the empty test tank m Intermountain r I Environmental Shade Covei Bailey Fischer I amp Porter i i l Dssumnonbn l Celesco
123. erged to four times its maximum rated depth If more than the standard 7 6 m of cable is required up to 914 m can be ordered Installation Place the sensor tip slightly below the lowest water level that is of interest to monitor Secure the cable to avoid changes in the sensor placement Maintenance If desiccant is not used this sensor requires basically no maintenance If the screen clogs with dirt it can be cleaned with a brush Test Results The WL300 was significantly affected by water temperature changes A 15 C decrease resulted in a 1 5 cm offset in output at a depth of 76 cm This problem is currently being addressed The sensor did show a high degree of long term reliability and excellent hysteresis and linearity The main problem arose whenever the sensor was allowed to dry for several days Dried silt on the sensor prevented it from working properly when it was placed back in the water This problem may fix itself after about half an hour The WL300 had over five times the reading instability than any other submersible pressure sensor Figure 47 ITRC work with other Global Water WL14 units showed extreme temperature effects Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 113 0 112 5 Sensor Output cm he eo 111 5 111 0 T T T T T T T T T 0 0 0 2 0 4 0 6 0 8 1 0 1 2 1 4 1 6 1 8 2 0 Time hours Figure 47 WL3
124. ers Wide range of uses for monitoring control and communications Large memory possible Primary disadvantages over other dataloggers Very difficult to use Must be programmed by the user Not easily used with industry standard hardware Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Campbell Scientific CR500 CR510 Datalogger 435 753 2342 http www campbellsci com Power Needs External Power Draw Number of Type of Input Accuracy Temp Logging Supply Battery amp hr day Analog Inputs Range Interval s 9 6 16 Y 0 3 1 1 depends 4 voltage or 2 0 2 5mV to 0 5V 0 05 25 0 02 sec VDC on settings current many others 0 40 C 50 C 2 5 hrs Size Storage Resolution Date Communications Relays Alarms Local Remote List Price Capacity Time Display Operations 21x4x10 24 000 13 bit Y RS 232 modem 2 5VDC Relays pager Optional Y w 760 w cm readings radio satellite max modem voice PC208W software 5002 modem software cable Price includes CR510 Datalogger PC200W and ShortCut software free SC929 RS 232 interface cable General The CR510 the new version of the CR500 is basically a CR10X with fewer inputs outputs and networking options Power The CR510 requires a single 9 6 to 16 V power supply The same power supply can be used to power
125. eter 2500 L 12 17 11 15 12 17 11 26 Figure 62 A Flars trending graph for the 2500 L Test Results The 2500 L is very easy to use and Flars is a very user friendly program The only problem encountered was with the interface cable that connects the logger to a computer The connection at the datalogger was very loose and sometimes had to be held firmly in order for any data to transfer Two dataloggers and two interface cables both had the same connection problem The logger clock was not affected by a power loss Due to the configuration of the sensor and datalogger datalogger accuracy could not be tested Ou 5 on 20 d 9d c Pal S28 E 5E o Beg gt E gt ZO zB o Za o a L Dog o 8 ao o g e S I d sso 08 o o E r amp Ex 3 d e v ge H As o o5 2 z Ss alae ee as 3 SS B9 5B o o Seal ne 2 amp mj 5b Eo Sb e 9 S erg A o o S 2226 lt L 4 Q9 M O c A gt no an em o 2500 L T 10 3 10 N Not tested 8 10 excellent 1 horrible Attached sensor not taken into consideration Other Models The Model 128 DCM is a compact datalogger unit independent of the 2500 ultrasonic sensor It has two input channels specifically for the 2500 and 3 analog 4 20 mA 0 20 mA or 0 2 V inputs An external 12 24 VDC power supply is required and no relays are available Water Level Sensor and Datalogger Testing and Demo
126. etup for pump control with a sensor or datalogger relay Lightning Protection While a direct hit can damage any type of instrumentation four precautions may help reduce the risk of damage because of a remote strike 1 Usea shielded cable to take the signal from the junction box or PLC to the control room 2 Make sure that the sensor output cable is shielded and that the cable shield is connected to the metal sensor housing 3 Ground the power supply and cable shield at the same earth ground point to avoid a difference in potential voltages 4 Use current capable surge protectors at the termination between the cable and the power supply or PLC and between the cable and the sensor if possible Miller 1998 See Figure 28 for clarification Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Surge Output Signal Surge Datalogger oe Protection Shielded Protection or PLC Common Ground Figure 28 Surge protection for a water level sensor The datalogger may require additional surge protection MTL Lightning Suppressors 888 746 4685 sells fully auto resetting DIN mounting surge protectors for 2 3 and 4 wire sensors as well as for serial communications lines A lightning suppressor for a 4 20 mA loop SD16X SD32X or SD55X costs about 90 A lightning suppressor for an RS 485 line SD16R costs about 1
127. f this report describes the unique test methods for that datalogger Data Analysis The maximum difference between the corresponding amp meter and datalogger outputs was converted to a percentage of the 4 20 mA range Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 3 General Information Power Definition When discussing a water level sensor power refers to the combined energy requirements of the sensor unit and its output loop Some sensors loop powered do not require any power over what is provided by the output loop When discussing a datalogger power refers to the energy requirements of the datalogger unit alone excluding any power that is routed to a sensor by the datalogger General There are two types of electrical power alternating current AC and direct current DC All batteries produce DC power and DC power can be easily produced from AC power using a converter 110 VAC is supplied from all standard U S wall jacks or can be produced from a battery using an inverter with some difficulty From 5 to 20 of power is lost in the conversion process While all sensor outputs are DC those that are not loop powered must also be supplied with a separate AC or DC power source For remote sites DC powered sensors and dataloggers are the practical option Excitation voltage input voltage required is either specified
128. ftware Price includes AxSys MPU Datalogger with one 4 20 mA input Downloading and data analysis software General The AxSys MPU is fairly simple to setup but the software for downloading and analyzing data is difficult to use The NEMA 4 enclosure has an LCD display and 4 button keypad on the front panel Several input options are available including two 4 20 mA loops but the datalogger supplies 18 24 V to each loop Power An exterior 10 17 VDC power source is required Power sources are available from Stevens Surge protection for the 4 20 mA loop is available Input The AxSys MPU can log serial RS 232 RS 485 or SDI 12 digital inputs or up to two 4 20 mA signals The 4 20 mA sensor s must be able to handle 24 VDC input Ower Options There are 6 input options for the AxSys MPU serial up to 8 multi drop sensors digital tipping bucket rain gauge one or two 4 20 mA inputs or two 4 20 mA and 6 serial inputs Serial inputs can come from a device using RS 232 RS 485 or SDI 12 In order to use the output current switches for control output AC or DC relay switches must be ordered The outputs on the sensor are only current switches capable of turning on or off an external relay A 4 20 mA output is also optional Mounting tabs make installation on a flat surface much easier For more memory and easier data transfer a 120 000 reading data card can be inserted into the lo
129. g After all sensor outputs stabilized at a depth of approximately 76 cm the 18 C water was drained and immediately replaced with ice water at 4 C After 10 minutes the water was again drained and immediately replaced with water at 49 C Over the next 50 minutes the water cooled by natural convection to 18 C Sensor and thermocouple outputs were logged every 5 seconds Data Analysis In Figure 13 the water temperature and water level sensor outputs are plotted on the same graph but have different axis Water level data were left out of the graph each time the water was drained and refilled to the previous level The sharp Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 change in sensor output during rapid temperature changes is typical of the submersible pressure sensors 80 60 78 45 o S 2 6 764 30 amp S o o o 74 15 72 0 0 15 30 45 60 75 90 Time minutes Sensor Water Temperature Figure 13 Sample water temperature fluctuation results submersible sensor Foam Effects Setup Air was pumped into the test tank by a compressor while dish soap was slowly poured into the water to form foam The foam was contained in a small area by a floating border constructed of wood Figure 14 Two staff gauges on the inside tank wall gave an approximate reading of the foam height Water Leve
130. g period Data Analysis The average output over the hour before the drying period was compared to the average output over the hour after the drying period Figure 18 displays the resulting offsets The individual results are given in the submersible pressure sensor section of this report Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 119 118 En N Sensor output cm o E a Dry for 20 days 114 113 T T T T T T T 1 0 0 0 2 0 4 0 6 0 8 1 0 1 2 1 4 1 6 Time hours Figure 18 Offset of submersible pressure sensors due to drying Output Stability Setup The same setup and water levels were used as with long term trending Testing The high water level was maintained in the test tank for two hours and all sensor outputs were recorded once per minute Data Analysis A plot of the output from each sensor was looked at for stability how much it oscillated around the average reading The results varied from 0 05 cm to 5 cm Figure 19 displays a typical plot As a group the ultrasonic sensors received the lowest poorest score This may be due to unavoidable surface waves due to wind or the underwater water inlet pipe While float sensors also measure the water surface they were installed in stilling wells Stilling wells dampen most surface waves Water Level Sensor and Datalogger Testing and
131. g protection can be provided Options When ordering the 2500 the user must specify if more than 30 meters of cable is needed between the sensor and the electronics enclosure An electronics component change will be required if the cable length is extended by more than 15 meters over the Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 standard 30 meter cable Up to 91 meters of continuous cable can be supplied with the unit In areas where freezing air temperatures are possible the optional transmitter heater and thermostat should be ordered to help to protect the electronics but it should be noted that they require extra power to run The Model 2500 L includes a datalogger see Badger Meter Datalogger and the Model 2100 is set up as an open channel flow meter Installation A bubble level and measuring tape are required for installation An L mounting bracket is supplied with the sensor but the sensor is easily installed on a 6 inch PVC flange or any horizontal surface with a hole in it It must be mounted far enough from any walls to accommodate the 3 beam angle The customer must provide a sunshade for the sensor The electronics enclosure is wall mounted with the screws supplied Calibration is well described in the instruction manual but requires the user to run through a half hour procedure with the front panel keypad To assure that the disp
132. g term trending Testing The test tank was filled with water to the top of the steel weir plate Ten readings were taken from each sensor at a 1 second interval To avoid error due to scaling to engineering units in Lookout the 32 bit readings output by the RTU panel were used After the water level was lowered several centimeters and allowed to settle ten more readings were taken This process was repeated at eight different water levels each lower than the previous one The true water level was read off a metric staff gauge and recorded for each data point The water level in the test tank was then raised by the same exact increments and sensor outputs were recorded again Data Analysis While this test was not extremely accurate it did expose some major problems with several sensors The ten readings for each water level were averaged to eliminate error due to waves or turbulence A 1 mm experimental error was included in the data analysis to account for the difficulty in accurately reading a staff gauge The maximum difference between a sensor output minus experimental error at any specified level when it was approached with an increasing depth and when it was approached with a decreasing depth was found This value was expressed as a percent of the full scale testing range for that sensor yielding hysteresis Figure 16 displays an example of high hysteresis Water Level Sensor and Datalogger Testing and Demonstration www itrc org re
133. g water Air Regulators When a compressed air tank is used instead of an air compressor an air pressure regulator must be utilized to slow the airflow out ofthe tank Due to the relatively large airflows recommended by many bubbler manufacturers a standard air regulator purchased at any welding supply store is sufficient A very slow bubble rate such as 1 bubble per minute will significantly increase the life of the air tank but will slightly affect the accuracy As a bubble grows on the end of the bubbler tube the Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 pressure reading will change slightly If high accuracy is not critical it is suggested that the bubble rate be set lower than suggested by the manufacturer This may require an additional pressure regulator in series Desiccant Some models that use an air compressor or atmospheric pressure line require desiccant to keep the sensor free of water vapor Installation Install the most shallow tube outlet about 15 cm below the lowest water level that is of interest to monitor Bubbler lines must be securely installed to avoid any change in position of the submerged end The tube may bend or curl over time so secure it as close to the submerged end as possible Some manufacturers provide a metal tube which is connected to the end of the flexible plastic tubing to help ease installation Se
134. gger However the user must also purchase a card reader over 900 for both As an alternative a 9 pin to 9 pin serial cable can be purchased from Stevens 30 or an Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 electronics supply store A 12 V rechargeable battery AC battery charger and AC power supply are available from Stevens Surge protectors for the 4 20 mA loop are 85 each The following options are recommended 9 pin to 9 pin serial cable 2V rechargeable battery Mounting tabs Wiring AxSys MPU Transmitter Figure 69 AxSys MPU wiring schematic for a single 4 20 mA input The 4 20 mA sensor must be able to handle 24 VDC Installation Screw the four optional mounting tabs onto the four corner holes on the back of the enclosure and mount the enclosure with screws or bolts To configure the AxSys MPU for a single 4 20 mA input complete the following steps 1 Interface the datalogger to a computer with a 9 pin to 9 pin cable 2 Apply 12 VDC to the power wires 3 Place the front panel power switch on A message should appear on the Stevens LCD screen The AxSys MPU can be configured with the front panel keypad or on the computer terminal but the keypad is easier to use The keypad has four keys up down and right arrows and MENU MENU enters new settings and advances the display to
135. gger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Electronic Enclosures General The National Electrical Manufacturers Association NEMA provides the most common rating system for electronic enclosures The ratings listed below apply for non hazardous locations when the enclosure is completely and properly installed These are not the full standards For more detailed and complete information consult NEMA Standards Publication 250 1997 Enclosures for Electrical Equipment 1000 Volts Maximum NEMA publications are available from Information Handling Services at 800 716 3447 ext 957 Table 5 NEMA electrical enclosure ratings adapted from NEMA 1997 Type of Enclosure Provides a Degree of Protection Against the Following Environmental Conditions 4 3 Incidental contact with the enclosed equipment x X Rain snow and sleet Sleet Windblown dust lint and fibers Hose down Corrosive agents Occasional temporary submersion Occasional prolonged submersion These enclosures may be ventilated ona External operating mechanisms are not required to be operable when the enclosure is 1ce covered NE External operating mechanisms are operable when the enclosure is ice covered Passive Cooling To protect sensor electronic equipment from direct sunlight and vandalism a NEMA 4 enclosure should be installed inside a T 1 steel box that allows passive cooling Figur
136. greater than 9 m If possible install the sensor deep enough so that it will be below ice that may form on the surface If the water could freeze around or inside the sensor it must be removed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 from the water before any ice forms A sensor can easily be crushed as water freezes around it When installing lower the transducer slowly into the water To avoid permanent damage to the diaphragm or electronics do not drop the sensor or strike it against a hard object Secure the cable so that it will not slip and change the depth of the sensor Cable harnesses are available from some manufacturers If the sensor is installed in a deep well the large amount of cable may stretch over time due to its own weight Druck includes a Kevlar cord inside the cable jacket to avoid stretching Otherwise some other type of support cable should be used Lightning Protection Submersible pressure sensors are extremely vulnerable to damage by lightning strikes because of their location in the water Electricity follows the path of least resistance and a submersible pressure sensor s cable is a low resistance route to water In some cases lightning strikes on the water will damage submersible pressure sensors making lightning protection especially important for this type of water level sensor If available from the manufac
137. h oh Ge S g amp o 2 e A E E 5 E 9 o s o n o g 2 a e B lig s E J e B Ip 5 S ogg as E S S 26 s8 9 2 m il Ez E ri ae lo 8 A o 2 m D D on 923 5 2 2 Poe ee dE 5 8 amp B E Hols 65 apv a gt S E e 3 S o en e Ss Slo B9 8e amp T 8 a 9 E E 5 O 9 E 33 o Boe Bg ua A c o 2 4 zS gt 2 g 2 D B e e ni E Zeta S S 5 AB IAS d 3 8 5 S n g o Ss o EF o n 2 S D Q o z 9 o LA mAlys 24 22 38 9 E 5 g o 5 39 8 8 3 az ss S Ja J S amp x Jc amp s x e BEBIS Ja 2 ly g amp 3 A B amp amp A S 6 a a S 5 5 z E O a A 210S 10 9 10 N 10 6 10 10 10 10 10 9 4 8 The lightning protection kit was not originally ordered New upgrades should make the unit more tolerant to surges 10 excellent 1 horrible Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period full scale 0 106 Max daily error during that 20 day period full scale 0 231 Advertised error full scale Other Models If ultra low level measurements are needed the Series 46R can measure the range of a 50 cm water column Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other submersible pressure sensors Wide range of options for many applications Warr
138. ial communications to RS 485 radio or microwave over long distances a simple cable an optical link or a modem A simple cable is usually an interface line with a 9 pin connector at one end and a device specific plug at the other Optical link cables also have a 9 pin connector at one end but the other end communicates with light so that the cable doesn t need to touch the datalogger Some dataloggers have internal modems and some have options for connecting to a modem Remote operations refer to the ability of the user to communicate with the logger or many loggers from a single point without having to go out into the field Most dataloggers have the ability to produce ASCII comma separated variable CSV or comma delimited files These files can quickly be inserted into Microsoft Excel 95 or 97 with the following steps 1 Open Excel 2 From the File menu choose Open 3 Under File of Type choose All Files 4 Find the correct directory and Open the CSV file 5 Ifthe Text Import Wizard window opens choose Delimited and click on the Next button Choose Comma and click on Finish Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Date and Time Stamping One very important datalogger feature is the ability to stamp each reading with the date and time While all dataloggers must have an internal counter to maintain the specified sample
139. ide surge protection Input There are a total of 16 analog input channels Fourteen of these can be used either for 14 single ended inputs such as 0 5 V which can have a common signal return line or 7 differential inputs such as 4 20 mA which must have individual signal return lines The remaining two channels which have 12 instead of 18 bit resolution can monitor unipolar single ended inputs such as battery voltage or internal temperature The first group of fourteen inputs mentioned can only accomplish 18 bit resolution at 2 samples per second The logger has 15 bit resolution for up to 16 samples second This means that if more than 2 sensors are hooked up and the required sample time is 1 second the logger will only have 15 bit resolution Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 The 15 digital inputs can monitor periodic wave frequencies or periods digital states high or low and tipping buckets rain gauges among others Options Memory capable of holding up to 2 million data points and expansion cards for up to 8 analog voltage outputs additional analog inputs or special sensor interfaces are available For use near an AC power source a wall socket power supply can be purchased One precision resistor must be purchased from Coastal Environmental for each 4 20 mA input Other options include Super Tran
140. ill only record data at a maximum rate of once per minute Assuming that all sensor data will be logged simultaneously enter the output interval in minutes at the top of report box 1 Enter 0 to disable the other two reports Click on report box 1 In the gray box to the left click on a sensor such as 4 20MA O Click Sample Average Maximum or Minimum to the log that value over each output interval Do this for each sensor As an example a sample could be taken every minute on the first report then the average max min could be recorded for each hour or day on the second report This can help eliminate the need for some calculations later but will take up memory space Once all datalogging is configured click Close 13 14 Click Go to Window in the Step 4 box Click OK This window tells the user where to connect the sensor wires to the CR10X for that specific program When fished click OK then Exit Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 To configure the CR10X using PC208W software complete the following quick start steps This section only covers the steps necessary to configure the CR10X as a water level datalogger without any control or long distance communications abilities If using PC200W software refer to the Campbell Scientific CR510 Datalogger section of this report 1 Connect the CR10X to a computer using a RS 2
141. interval they do not all keep track of the actual date and time The data transfer software can use the PC clock to assign a date and time to each reading after the data is downloaded If power was lost during recording some or all of the data points could be assigned an incorrect date and time Date and time stamping eliminates that possibility Alarms When a datalogger has alarms it can mean many different things An alarm is any user defined automatic datalogger or sensor response to a high or low water level low battery power full memory or other abnormal condition Alarms include a flashing light emitting diode LED on the datalogger dialing a pager or caller ID telephone sending an alarm report over a modem and activating one or more relays Calibration Some dataloggers allow the user to calibrate the ampere or voltage inputs The user can insert an amp meter into the current loop or measure the voltage with a volt meter across an external resistor for a 4 20 mA sensor or measure the voltage across a 0 5 V sensor with a volt meter The datalogger reading can then be calibrated to match the meter reading The usefulness of datalogger calibration depends entirely on the meter being more precise than the datalogger Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Datalogger Comparisons Multiple sensor inputs and advanced cont
142. ion PS9800 Submersible Northwest Pressure Transmitter KPSI 210S j Submersible Pressure Transmitter d Sensor Brand EE Sensor Model a Oo ua l 479 w 6 m cable desiccant 778 1 078 w desiccant 6 m cable lightning protection depends on accuracy 707 w 6 m cable EE Stevens SDT II Submersible Pressure Transmitter 10 excellent 1 horrible NA not available SW stilling well required SW stilling well recommended Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf Table 7a Sensor specifications Sensor Brand ELE a c w 2 e go s Bailey Fischer amp Campbell Scientific Scientific amp hr day Power Supply Power Draw Average 12 14 VDC or 117 230 VAC 110 120 or 220 240 VAC 50US3000 SR50 9 16 VDC 0 05 6 depends on interval 18 36 or 12 0 3 2 wire loop 36 VDC or powered 90 127 VAC DCU 7110 10 30 VDC Prosonic T FMU 230 1 7 at 24 VDC The Probe Loop 0 75 w 4 20mA 100 115 230 output includes datalogger VAC d B Mi 12 VDC or 120 VAC Reactive Air System 4 20mA RS 232 4 relays L1A 24VDC or 0 5A 120VAC 4 20mA 2 relays 0 3A 30VDC SDI 12 Pulse Train or serial ASCII 4 20mA RS 485 relay FTU only 5A 250VAC or 100VDC 4 20mA 1 relay 5A 250VAC 4 20mA 2 RS232 RS
143. ional 4 20 mA output ports Only the bubbler level monitor and the datalogger were tested for this study The datalogger section discusses general characteristics of the Sigma 950 in more detail All electronics and hardware for the bubbler are installed inside the Sigma 950 NEMA 4X 6 datalogger enclosure rated 4X 6 even with the door open There are three air flow ports utilized intake reference and bubbler A single vinyl tube is connected to the bubbler line port and submerged at the other end A small amount of air is continuously pushed through this tubing The intake port supplies the internal air pump with fresh air which is drawn through three filters and a desiccant tube The reference port provides a reference to atmospheric pressure and is also protected by filters and desiccant The internal pressure transducer reads the pressure in the bubbler line and periodically switches to atmospheric pressure for a comparison At a regular interval the bubbler port Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 and reference port are electronically zeroed by switching to open air simultaneously The 950 can be programmed to automatically purge the bubbler line at an adjustable interval Power The 950 can either be run off a 12 VDC battery or AC power Lead acid gel and Nicad rechargeable batteries are optional If running off AC a power converter m
144. ists on each side of the valve A circular stilling well can range in diameter from 4 to 48 inches depending on the application Intake pipes require occasional cleaning which is usually simpler with a larger pipe USBR 1997 Large diameters are useful for easy access as well as for viewing a staff gauge mounted on the inside wall Installation 1 The pipe connection to the stilling well wall and the flow channel wall should be cut flush with the side wall to avoid velocity impact on the stream side USBR 1997 2 Install the opening of the stilling well in an area of low flow so that pe z 0 01xA 9 28 where v is the water velocity g is the gravitational constant 9 81 m s and A is the head reading Replogle 1997 3 The pipe connection should be 30 90 cm above the bottom of the channel if possible to avoid plugging by sediment in the channel 4 A2 inch vertical flushout tube installed in the pipe connection makes maintenance easier A valve in the access tube between the stilling well and the flushout tube can be closed and compressed air or pressurized water used to blow dirt out Figure 29 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 d lt D gt Must be flush w side wall Channel Stilling d Well lt gt a v 30 90 cm f n if possible Valve for on off only Figure 2
145. itched External 1 year 7 2 5 A wide range of solar panels can be purchased from Real Goods at 800 762 7325 A charging regulator must usually also be purchased to avoid overcharging the battery Figures 22 and 23 give examples of compact low power independent sensing and datalogging units Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 4 20 mA Loop ACR OWL 500 Powered Sensor Current Logger BE 12V 10AH Sealed Rechargeable Battery Figure 22 A low power setup which requires battery replacement once per month Depending on the sensor a single unit costs about 1056 Software extra batteries and a battery charger must also be purchased Table 2 Components for a sample battery powered compact setup ACR OWL 500 Datalogger ACR 800 663 7845 299 Druck PTX 1230 1830 Druck 203 746 0400 595 995 Submersible Sensor Power Sonic 12V 10AH Power Sonic 650 364 5001 42 Sealed Battery Representative Submersible Sensor Desiccant KPSI 800 328 3665 15 Tube 951 1351 4 20 mA Loop ACR OWL 500 Powered Sensor Current Logger Charging Regulator Batt Batt PV PV m ii 12V 1 2AH Sealed Rechargeable Battery 5W PV Array Figure 23 A solar
146. k PTX 1830 to water temperature fluctuations 98 Figure 47 WL300 output for a constant water level and temperature 101 Figure 48 Long term drift in the Instrumentation Northwest sensor calibration 104 Figure 49 Basic bubbler pressure sensor layouts Each type may or may not have a valve that controls atmospheric pressure referencing sss 111 Figure 50 Flowchart for selecting a bubbler sensor for a specific application 114 Figure 51 The low impact of water temperature changes on the American Sigma 950 MSU y eme RC ETE e A AA 118 Figure 52 Response of the Digital BLM to water level changes sample time 30 Seconds sas ee re a E Re rd A et M Am d Ee ed EE 123 Figure 53 A leaking Tesco reactive air monitor during the air temperature fluctuation test The leak is due to incorrect installation by the user The bell purged every 12 hours resulting in the output spikes sse 128 Figure 54 Four basic datalogger layouts eese eee eese eese tentent et nnaa 130 Figure 55 Flowchart for selecting a datalogger for a specific application 133 Figure 56 Three common OWL wiring schematics The DC power source must be within the voltage input range for the sensor sse 138 Figure 57 A TrendReader trending graph for the OWL sse 140 Figure 58 Three common SmartReader wiring schematics
147. l Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Figure 14 Dish soap foam forming beneath an ultrasonic level sensor It was leveled off prior to taking readings Testing Water level readings were taken with each sensor when no foam 10 cm of foam and 20 cm of foam were present A flat blade shovel was used to even off the top of the foam before each reading was taken Data Analysis The sensor outputs were later re scaled over the original calibration range so that the sensors gave identical water level readings when no foam was present In other words all sensors were originally calibrated with two water depths 91 cm and 114 cm If the sensor output had drifted the outputs were re scaled so it would again read correctly at these two points This simply makes for a more accurate comparison The test results are presented in the ultrasonic sensor overview section of this report Time Lag Setup The same setup and water levels were used as with long term trending Testing Water level readings were recorded once per second From a starting depth of 91 cm the water level was raised to a depth of 114 cm in approximately 6 minutes The Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 high water level was maintained for five minutes and then dropped back down It took approxi
148. lars software for Windows 300 Interface cable General The Model 2500 L is an ultrasonic sensor and datalogger in one unit The sensor and datalogger are also available as separate components the Model 2500 ultrasonic sensor and the Model 128 DCM datalogger When the Model 128 DCM datalogger is purchased as an independent unit 750 it has three 4 20 mA or 0 2 V Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 inputs and two inputs for Badger Meter flowmeters For more information on the ultrasonic sensor refer to the Badger Meter Ultrasonic section of this report Power 117 230 VAC or 12 14 VDC can power the 2500 L The entire setup sensor included draws approximately 87mA with no relays activated and up to 100mA with relays activated Protection against line surges is standard and additional lightning protection can be provided Input The datalogger component of the 2500 L receives a digital signal from the sensor electronics The two digital input channels of the 128 DCM can only be used for Badger Meter 2500 ultrasonic sensors but the three 10 bit analog inputs can be used for any 4 20 mA or0 2 V signal This datalogger also allows for a pulse or contact closure for totalization or rain gage gauge inputs Options There are not any options for the datalogger when integrated with the ultrasonic sensor The datalogger can
149. lay reads the actual water level set the offset to the distance from the maximum fluid level to the face of the sensor Set the span to the distance from the channel or tank bottom to the face of the sensor minus the offset value Maintenance To maintain the Badger Meter check the distance calibration every three months as described in the instruction manual Test Results Of all the ultrasonic sensors tested the Badger Meter was the only one to successfully penetrate through dish soap foam This is most likely due to this sensor s relatively small beam angle and powerful signal However the test did not test whether the sensor would penetrate through the organic foam found on the surface of many waterways Among ultrasonics it had an average response to air temperature fluctuations and surface waves As did most of the ultrasonics the 2500 displayed almost perfect linearity hysteresis close to zero and excellent long term reliability Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 GH 6 o o a 2 g n o K Bg n 2 A 3 1 oh E a7 a D 8 8 85g 9 e5 s e 9 2 i IE B ow 3 a s 28 SEIS a S 2 x R S EB S S I ESIA AZIE S amp A 5 5 3 o 63 8 m es oe lS E a S ia 9 3 5 9 S x 9 S o A 9 ee PA Q pe 3 5 s 2 EH 5 a ex ej 2 ps g 2 s slegla zsle e B P I
150. ls are good bird deterrents and will help to keep the array clean Latitude PV Array Figure 26 PV array installation for a fixed mount Maintenance Keep the solar panel free of dirt and dust Cut bushes and trees to avoid shade on the cells Relays Some sensors are available with one or more relays A relay is an electric contact for activating or deactivating other equipment such as pump contacts alarms or pagers The user sets alarm conditions during the sensor or datalogger calibration usually a high or Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 low water level When an alarm condition is met the sensor closes or opens the relay loop An extra power supply is usually needed since the sensor or datalogger itself does not supply current to the relay As an example when the water level in a channel is too low a relay closes a contact to start an extra pump When the water level is too high another relay opens to stop the main pump Some relays open when power is applied and other close when power is applied The sensor or datalogger will use less power if the default setting is the one that is used the most Since sensor and datalogger relays can typically handle only a small current and voltage a separate slave relay usually steps up the power Figure 27 b Sensor or Datalogger Pump Contactor Figure 27 S
151. mately 15 minutes for the water level to stabilize at 91 cm after which the cycle was repeated again Data Analysis The sensor outputs were later re scaled over the original calibration range so that the sensors gave identical water level outputs at the first point and at the highest point on the graph Figure 15 gives a sample lagging output Adjusted Sensor Output cm 0 10 20 30 40 50 60 70 Time minutes Actual Water Level Sensor Output Figure 15 Sample time lagging output graphed along with the actual water level Wave Effects Setup The same setup and water levels were used as with long term trending A one meter section of railroad tie was used to make surface waves Testing Waves were produced in the test tank by pushing down and letting up on the floating railroad tie in a steady rhythm First 10 cm waves from crest to trough were Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 created at a 1 sec frequency After 5 minutes the surface was allowed to settle for 15 minutes Then 2 5 cm waves were made at a frequency of 2 sec for 5 minutes Data Analysis The water level readings from all five ultrasonic sensors were plotted versus time The results are given in the ultrasonic sensor overview section of this report Linearity and Hysteresis Setup The same setup and water levels were used as with lon
152. monstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 surge protection in the junction box and at the sensor to protect against lightning strikes 85 each Options Ranges as low as 0 2 5 feet 0 0 76 m and as high as 0 100 feet 0 30 5 m are available Specify the cable length needed from the sensor to the wire termination enclosure when ordering Standard 1 pipe threads are provided on the end of the SDT II A tank mounting kit can be ordered for installation into the side of a tank or weir The sensor can also be secured to a wall using a bracket mount or to the bottom of a channel using a clip mount Since the sensor is primarily made of PVC a weighted sleeve and stainless steel cable called the down hole kit must be attached for dropping down a stilling well The following option is recommended Down hole kit for installation in a deep or small diameter stilling well Installation Installation of the SDT II is a little more complicated than with most submersible pressure sensors The wire termination enclosure has to be mounted somewhere nearby and the sensor itself must be weighted or secured to a solid structure Place the sensor tip slightly below the lowest water level that is of interest to monitor Do not simply lower the sensor into a stilling well The SDT II s low density allows it to change position easily Maintenance Replace the wire termination enclosure
153. must be reordered from Sigma Part No 787 Remove debris that is hung up on the bubbler line as needed Test Results Among the bubblers tested the Sigma 950 performed well There was no apparent lag in response time to changing water levels and the bubbler displayed excellent linearity and low hysteresis Air temperature changes had almost no affect and water temperature only disturbed the water level reading at very high temperatures Figure 51 The 950 had to be returned to the manufacturer for installation of a 4 20 mA output so no long term data are available Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 80 r 60 78 45 Sensor Output cm N o 69 eo Water Temperature C 74 72 0 15 30 45 60 75 90 Time minutes Sensor Water Temperature Figure 51 The low impact of water temperature changes on the American Sigma 950 bubbler ge En op Ge g amp H o g 5 8 5 4 un 2 m amp Bax E F E 2 2 8 E Is J 3g 8B B e J E z 9785 3 2 a me 3 gt S 2 4 c Iz og 4 S O 29 8 a S o 7 ium SS xs RS S 5 9 a oo Ss 5 a gt 5 2 o S 9 S88 S m 8 3 28 16 2 m fS 9g 2 e gt 3 zoe SEIBEIS E aj p lt 45 Belo oa BS IS ASIA IS 5 gt 2 5 E S NEM 2 28 ve Jgs lg gt E EB z 2 D PEE o mAlS 9195 45 5 z 3 A do gt E A 4 8 E EZES
154. n as opposed to the more standard stainless steel housing with O ring seals Titanium is more resistant to corrosion which helps for applications in water with high mineral or low oxygen content The lack of O rings is advantageous if the sensor will be dry for extended periods of time O rings can dry and crack if dried and heated often The electronics are encapsulated so that any moisture that makes its way down the vent tube will not permanently harm the sensor The sensors are NEMA 6 rated the only submersible pressure transducers studied at the ITRC with a NEMA rating The cable comes standard with a Kevlar cord 54 kg breaking strength inside the polyurethane jacket which is used to tie off the cable above water This will help avoid Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 cable stretching especially in applications where a large length of cable is required Several useful options are available Power 9 30 VDC is required across the transmitter terminals The PTX 1230 and 1830 have a 4 20 mA output but other models are available with a 0 100 mV signal No internal lightning protection is available but optional lightning arrestors are available for installation at the wiring end of the cable Beginning the summer of 1999 lightning protection will be installed in the PTX 1830 and PTX 1230 at no extra cost However additional prot
155. n order Bailey Fischer Endress Damped Milltronics Damped Badger Damped Lundahl Co o N o Adjusted Sensor Output cm I 10 I I 10 cm waves gt 1 sec 0 5 10 15 20 25 30 35 40 45 50 Time minutes Figure 34 Ultrasonic sensor outputs during wave activity Foam Sound waves reflect off and are absorbed by any surface so foam can easily alter an ultrasonic water level reading Foam tends to absorb the ultrasonic pulses and reflect them in many directions which can result in a lost signal Figure 35 shows ultrasonic sensor response to two depths of dish soap foam on a level water surface The ability of an ultrasonic sensor to penetrate foam grows with decreasing beam angle see Figure 32 and increasing strength of the sound pulses Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 120 105 Actual Water Level Y Adjusted Sensor Output cm e eo NI oa 60 Bailey Fischer amp Endress Hauser Milltronics Lundahl Badger Porter H No foam El 10 cm E120 cm Figure 35 Foam effects on ultrasonic water level sensors Lost Echoes In some situations an ultrasonic sensor can lose its echo This means that enough of the ultrasonic pulses are either absorbed or reflected away from the sensor so that no echo can be detected In Figure 35 the Lund
156. n the corner of the SmartReader housing allows it to be locked in place with a standard padlock Unlike the OWL it must be installed inside a watertight enclosure Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 To configure the SmartReader Plus in Windows complete the following quick start steps l 10 11 12 13 14 Plug the interface cable into the jack on the SmartReader and connect the other end to a PC Follow the installation instructions on the TrendReader disk label Open TrendReader and from the Communicate menu choose Preferred Logger and SmartReader Plus 12 Bit or SmartReader 8 Bit From the Options menu choose Units and DC Current and select MilliAmps for a 4 20 mA input For voltage input choose DC Voltage and select Volts If Microsoft Excel will be used for data analysis from Options choose Save as ASCII after Backup and Comma Separated CSV Double click on the COM icon for the port occupied by the interface cable If it is unclear which port the cable is connected to try each icon until the status window opens Click Edit Setup If the logger should stop taking readings when the memory is full choose Stop When Full Disable any channels that will not be used click in the ON column until is reads NO for those channels and enable any channels that will be used click in the ON column until it reads YES for
157. nalog readout only displays in percent full scale If used for measuring flow a totalizer and or flow recorder are also available A 7 6 m length of cable to connect the transducer and transmitter is standard and optional extension cables can be ordered If more than 61 meters of cable is needed specify this when ordering the unit so the transducer and transmitter can be matched a factory procedure Finally pipe or flange mounting options are available The following option is recommended Digital display Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Installation Installation is basically identical to the Badger Meter except that the transducer mounting bracket includes a permanent circular bubble level This standard accessory makes installation a bit easier The beam angle is approximately 6 refer to Tables 8 and 9 and the transmitter is wall mountable The calibration procedure is easy once understood but it may take a few minutes to find and figure out the many switches on the circuit board Calibration should take about half an hour Be sure that the Test switch is set to 0 during calibration and normal operation A measuring tape and or staff gauge will be needed to determine the span distance from the lowest water level to the highest water level and zero the distance between the transducer face and the lowest water
158. nd Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 to changes in cable tension to about 1 mm or less for a 1 1 m range sensor A 20 cm diameter float may also be acceptable with errors due to changes in cable tension at about 2 mm or less Replogle 1997 Maintenance Maintenance is also easy The potentiometer may need replacement every few years especially if the water level vibrates around a certain point for much of the time dithering Test Results The Celesco PT420 was not significantly affected by air or water temperature fluctuations and linearity was almost perfect Hysteresis was much better than average among the sensor tested S 2 H v o 3 R v g 6 a a z na on G E T 5 2 Ols Balls o o g B o pe en p m E ui a 3 5g a 9 D 5 2 228 e Jasal REI S E S 2 J 3 s J Holz 5 Bela Ass amp z 5 3 ET E o o8 a Te ey OR o S EA E S 5 E LA 3 O8i4 JG ES S9s a 4 5 cm g J sle 3 Sg Eales B e B RO IS J3 13 EA SR S amp B8 S E 3 3 2 o En amp S 8 8 B amp B 8 538 6 ee I J J ra m aa ga ae o m O 3 Bg S 9 S H A o 3 v E E PT420 10 7 10 10 N 9 10 Stilling Well 10 9 10 9 NA 10 10 excellent 1 horrible NA not available Other Models If splashing overtopping or wet weather conditions are possible Celesco also offers several water resistant posi
159. nding Setup Once most of the water level sensors were installed and calibrated in the test tank a 4 hour pump cycling routine was run 2 hours on 2 hours off controlled by Ladder Logic programming in the Micro 16 controller When the pump was on water spilled over the top of a rectangular steel 2 99 x 1 14 m weir plate see Figure 8 When the pump was off water spilled only from a 15 3 x 4 5 cm rectangular hole cut in the weir plate Figure 8 resulting in a water level drop of 23 cm The exact water level was Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 determined with a millimeter staff gauge mounted on the tank wall A garden hose fed water continuously into the tank to offset leakage on the weir plate thereby ensuring that while the pump was turned off water always flowed over the lower edge of the orifice Figure 8 Rectangular weir plate in the test tank Front view showing rectangular spill orifice linearity test points rubber stoppers and clamps regulating the orifice size Testing Temperature data were logged once per hour and water level sensor output data were logged once per second No data were logged for 15 minutes after the pump turned on or 15 minutes after the pump turned off to allow the water to stabilize at the new level Data Analysis From June 1 1998 to September 27 1998 every fourth day of data were plot
160. nectors on the CR510 Install PC200W by double clicking on the Setup icon Open PC200W Click Add Logger Scroll down and highlight CR510 then click OK If COMI is not being used click on the correct COM port gu oA copo SPOS Click Connect If the computer is connected to the datalogger correctly the Logger Date and Time will appear in the Logger Clock section of the screen 7 Click Set Now to synchronize the datalogger date and time with that on the computer 8 Click Send and find the CR510 program created with ShortCut Click OK 9 To download data from the logger click Data Collection and determine the data file name and location then click Collect Now The data is saved in a CSV format Maintenance Keep the datalogger enclosure free of moisture Data Analysis Data is saved as a CSV file unless otherwise specified by the user and can later be analyzed with a spreadsheet program such as Excel Test Results The Campbell Scientific CR510 is very difficult to use especially the first time If an application is outside the scope of ShortCut the user must program the datalogger using Edlog Campbell Scientific s programming language The large volume Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 of reading material that comes with the CR510 is not very useful Only the ShortCut software allows the user to configure the datalogger for sim
161. ng fluctuating water temperatures Figure 46 The short changes in output during extreme changes in temperature which would not be seen in actual applications were due to the time needed for the internal electronics to heat or cool to the same temperature as the sensing element The sensing element is in direct contact with the water so it changes temperature much more rapidly Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 80 4 60 78 4 45 o 5 S m a gt MP EE nd 6 76 30 E o o 74 15 72 4 0 0 15 30 45 60 75 90 Time minutes Sensor Water Temperature Figure 46 Response of the Druck PTX 1830 to water temperature fluctuations 3 en en E E E eo e 88 a o Z a ls 29 8 B 2 e p 2 B8 9 8 S89 8 388 amp 9 2 BOB B n Salg Ses amp les les a 9 8 w e S 2 og O 2 B S E o t mH S z iS B T BS ur asaz E 5 gt 5 ES D S on S S 8 B9 B8gja8 2 T E o E r blg zoop Eal g n a r o S z2 8 S8 2 3 a fa E71 n E B Bi gt S ASIAA ag T gt 3 5 S BERI BS vE Jgn lZ gt B8 amp L E 2 p Es lo 2 7 g Sx 28 5 9 5 2 5 w 16 2 3 2 3 sales Hd 2 o S e g T gi E z g EBJE 5 H Ez Q 3 E E amp 8 h 7 g B na S 5 5 z e 9 e A PTX 1830 10 9 10 N 10 8 10 10 8 9 7 9 8 8 10 excellent 1
162. ng and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 11 Important fields for basic calibration of the Endress Hauser Prosonic T FMU ao i us HeHo Hs m Measured Distance from Distance from ey ee water level sensor face to lowest to highest liquid damping lowest water level water level Lineari zation Extended parameters V8 Current output i Lost echo Operating 0 linear 4 20 delay time Parameters V9 Service Simulation Commu nication Read only Maintenance No special maintenance is required Test Results The Prosonic T FMU 230 performed below average among ultrasonic sensors during fluctuating air temperatures and about average on foam penetration However the sensor had almost perfect linearity and very low hysteresis As with all ultrasonic sensors tested at ITRC the Prosonic T has excellent long term reliability m 6 o T 5 5 g B Fi 2 S 6 a a Salm s a m 5 9 2 8 g e O5 35 EZB op 2 5 e B E J 22 l8 E lg ale SEIS a 8 2 8 E sS sg x e un mH E 5 S 5 22 0 As B e a 2 ES 2 or R 9 SRITIS z a onlo g a T S iu a 2 Sj 3 Psls 22 5 A E la meme er um B S Bud E E 5 2 a E 2 gt Ac o o Es B5 og 3 o 3 o 1 3 a A amp EIS eee E 2 E o amp 8 Jo E al m gm D 5 a 9 E 9 E eZ 2 5 Q 4 E oO 9 S d a 4 E E FMU 230 5 8 5 10 Optional 2 2 Adjustable 10 8 6 9 10 7
163. nge loop powered powered powered Angle FMU FTU 230 0 25 Am Optional Optional Optional 5 5 FMU FTU 231 0 4 7 m Optional Optional Optional 5 5 FMU 232 0 6 15 m NA Optional Optional 3 The following options are recommended 2 wire loop powered unless AC is available or gt 7 meter range is needed LCD display Installation Physical installation is relatively simple with the optional mounting supplies A bubble level is needed to install the unit vertically Install the face of the 230 at least 25 cm and the 231 at least 40 cm from the maximum water level See Table 10 for the ultrasonic beam angle Follow the Connection Diagram in the Electrical Connection section of the operating manual if the wiring is confusing Calibration of the Prosonic T involves the Endress Hauser operating matrix which may take a while to figure out The matrix is basically a way of organizing information within the memory Table 11 displays the matrix fields that are used for basic calibration To alter a matrix entry shaded fields cannot be altered press V until the appropriate row is reached then press H until the appropriate column is reached Then press or and the entry will begin to flash Change the entry by pressing or Once the correct entry is obtained press V or H to confirm See the Operating via the Matrix page in the manual for other commands Water Level Sensor and Datalogger Testi
164. nsor Calibration software and interface cable General The Lundahl DCU 7110 does not have a local display keypad or switches but instead is calibrated with a user owned computer An RS 232 cable and software both ordered separately are used to interface with DOS or Windows While a computer is not Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 required to install this NEMA 4X sensor it is very helpful When powered the sensor emits a constant stream of ultrasonic pulses The return signals are not averaged but four echoes must be received in a row within about 6 mm of each other for the sensor to output a reading If this does not occur the sensor outputs a maximum distance zero depth Power The DCU 7110 needs a 10 30 VDC power supply so it can easily be run offa 12 VDC battery At 24 VDC it draws a constant 70 mA Only a 0 5 VDC output is available and no surge protection is supplied Options The octagonal plated steel mounting clamp makes physical installation of the sensor easy A stainless steel clamp is also available but is only needed in extremely corrosive environments The sensor comes with 6 feet 1 8 m of cable standard but up to 50 feet 15 m can be ordered at an additional cost Also order the computer software and hook up cable 15 The following options are recommended Octagonal mounting clamp Soft
165. nsor for good operation Several output options are available including 4 20 mA An internal diode with a 40 V breakdown is standard in the LEVEL WATCH and additional external lightning protection is available Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Options Measurement ranges of 4 11 30 and 100 feet 1 2 3 4 9 1 and 30 5 m are available the 4 in LEVEL WATCH 4 means that it has a four foot range Only 0 3 m of vented cable is supplied standard so extra cable must be ordered at 1 50 foot 4 92 m The desiccant replacement is 48 and is needed unless a dry wire termination enclosure is available A water conductivity sensor and or water temperature sensor can also be housed in the same sensor The following options are recommended Extra vented cable Installation Place the top of the sensor slightly below the lowest water level that is of interest to monitor Secure the cable to avoid changes in the sensor placement Assemble and mount the desiccant replacement filling the diaphragm to about 1 3 full Over or under inflation will result in errors in the sensor output Maintenance A new vent tube may out gas for a period of time Check the air bladder periodically especially soon after installation to make sure that it remains about 1 3 full Pull any visible obstructions out from the water inlets on the top of the sensor a
166. nstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other dataloggers Very easy to set up and use User friendly software NEMA 4X enclosure Primary disadvantages over other dataloggers The single input is reserved for the Badger Meter 2500 ultrasonic the 128 DCM is a separate unit with the same datalogging characteristics but has 3 analog inputs and 2 inputs for Badger Meter ultrasonics Very bad interface cable connection Campbell Scientific CR10X Datalogger 435 753 2342 http www campbellsci com Power Supply Needs External Power Draw Number of Type ofInput Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s 9 6 16 VDC Y 0 3 1 1 depends 12 voltage or 0 2 5mV to 0 5V 0 05 25 0 02 sec on settings 6 current many others 0 40 C 50 C 2 5 hrs Size Storage Resolution Date Communi Relays Alarms Local Remote List Price Capacity Time cations Display Operations 23x9x7 62 000 13 bit Y RS 232 8 SVDC Relays pager Optional Y w 1 410 w cm 1 million modem radio max modem voice PC208W PC208W readings satellite 5000 modem software cable Price includes CRIOX datalogger PC208W software 285 not needed for some uses PC 200W and ShortCut software free C929 RS 232 interface cable General The CR10X datalogger is capable of advanced mea
167. nterested in automatically measuring and controlling flows into canals for example In addition districts are interested in automatically measuring spill flow rates from canals d Measurement of water levels at farm turnouts An example of this need is found in the Newlands Project in Nevada where the large flow rates short durations of deliveries and flat topography all combine to require automated water level sensing on flow measurement flumes Electronic water level sensing equipment is really composed of two different units The first unit is the water level sensor itself Among other factors there are differences in cost robustness accuracy power requirements and ease of calibration between various designs and manufacturers The second unit is the electronic equipment that senses an electronic signal from the sensor typically a 4 20 milliamp mA or a 0 5 volt V signal For item a above this electronic equipment is typically a large PLC Programmable Logic Controller which Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 performs many functions including reading the sensor communicating with the office and controlling the gate For items b c and d the datalogging recording equipment is typically a smaller unit which has no control capabilities In some cases the datalogging recording equipment can be generic 1 e not
168. obal Water WL300 has a metal screen at the tip of the sensor to protect the pressure sensing diaphragm from debris in the water The number of openings in this screen should help prevent clogging in dirty water but its position may allow bubbles to collect on the underside of the diaphragm This may pose a problem in situations where the entire sensor dries periodically This sensor is unique from all other submersible pressure transducers studied in that the manufacturer claims it does not require the use of desiccant or an air bladder The electronics are sealed in epoxy so that water vapor that works its way down the vent tube will not damage the sensor However if enough water Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 vapor condenses within the vent tube to form a droplet the sensor output will be adversely affected While not necessary it is recommended that desiccant tubes be purchased from another manufacturer for use with the WL300 KPSI sells color changing chemical desiccant tubes for 15 each Power A 10 36 VDC excitation is required and the output is a standard 4 20 mA signal Some surge protection and electronic temperature compensation are built in Options Several operating ranges are available from 0 3 feet 0 0 9 m to 0 150 feet 0 46 m Order the lowest range possible but the sensor will be damaged if subm
169. ogram Type in a name for the program and click OK Click CR10X CR10 and OK in the Pick Datalogger Type window Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 10 11 12 15 Click Go to Window in the Step 2 box Enter a Scan Rate sample interval in seconds and click OK For a sample interval shorter than 1 second the program must be altered later using PC200W or PC208W In the box in the upper left are four types of water level sensors Click on the categories to choose between them Water Level has the configurations for many specific sensors including those listed in the Input section above If using a 4 20 mA sensor with the current shunt TIM or a 1 5 V sensor with the voltage divider TIM click on Custom and then click on 4 20MA O in the gray Available Sensors box Click Add Enter a Level Input Location Label a name for the sensor the Measurement corresponding to 4 mA the lowest water level that the sensor can read and the Measurement corresponding to 20 mA the highest water level that the sensor can read Click Add Add other sensors as desired then click Close Click Go to Window in the Step 3 box There are three reports possible with ShortCut The items listed in the gray box for each report will be logged at the interval specified at the top of that box Even though the scan rate step 5 may be lower the logger w
170. ompanies such as Micro Ohm 1 800 845 5167 Precision Resistive Products 1 319 394 9131 Precision Resistor Co 1 727 541 5771 or Riedon 1 626 284 9901 Transducer vs Transmitter Despite the fact that the terms transducer and transmitter are often used interchangeably they have very different meanings Basically a transducer has a voltage output and a transmitter has a current output In this report both transducers and transmitters are simply referred to as sensors Submersible pressure transducers are called submersible pressure sensors and so on A transducer is a passive device that changes resistance as the measurement changes The datalogger or PLC sends a fixed current through the transducer and measures the voltage across it which is proportional to the transducer s resistance equation 2 A transmitter changes resistance as the voltage across it and or the measurement changes Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 A current proportional to the measurement is allowed through the transmitter as is the case for sensors with a 4 20 mA output Accuracy and Resolution Sensor resolution is the smallest change in water level that can be detected by the sensor Accuracy is the ratio of the error to the full scale output or the ratio of the error to the output as specified expressed in percent how close the scaled sensor out
171. ontinue taking data BoxCar has a useful help file The datalogger can be configured for a delayed or triggered start for configuration away from the measurement site and an adjustable data averaging routine A single LED can alert the user if the reading ever went outside of a specified measurement range Maintenance Replace the 9 V battery as needed The desiccant inside the AquaPod should be replaced when the humidity indicator shows pink in the 30 dot Data Analysis BoxCar will graph and print data in the format of Figure 68 and put data in a table Data can also be exported to tab delimited comma delimited or space delimited files Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 23 22 2 1 2 0 1 4 Feet 8 P B Water Level EEUU 31 00 32 00 33 00 34 00 35 00 23Nov38 10 31 00 TEST S N 141323 Figure 68 A BoxCar Pro trending graph for the AquaPod Test Results The AquaPod datalogger was very easy to set up and install To test the AquaPod for accuracy the datalogger output was recorded at several points within the 3 foot range The position of the beaded cable along a staff gauge was also recorded The differences between datalogger outputs were compared to the corresponding cable displacements and a maximum percent error over the full range was calculated as 1 6 Y on Ses 50 S Ou ye gc g
172. or does not require any maintenance current so it is well suited for low power applications The current draw while taking a reading is only 4 mA A big disadvantage is that only a 0 5 or 0 2 5 VDC output is possible instead of the more standard 4 20mA output The sensor is compatible with several dataloggers including Intermountain Environmental s AquaPod system Options When ordering the FP10C only three options are available measurement range length of beaded cable and a mounting kit The only difference between the 3 5 and 10 foot 0 9 1 5 and 3 m range sensors is the number of turns the potentiometer can take A sensor with a 3 foot 0 9 m range will include a 3 turn potentiometer and so on The Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 length of beaded cable required equals the distance from the lowest anticipated water surface to the location of the sensor plus about 1 m The mounting kit is designed to make leveling the system easier Installation Installation may be a difficult task unless a suitable stilling well is already in place The sensor must be bolted onto a horizontal surface directly over the stilling well with room for the cable on either side ofthe pulley The instruction manual does an excellent job of describing how to completely install the sensor Maintenance Maintenance is simple Every 4 5 ye
173. ough from walls to prevent the signal from hitting them The minimum distance from the sensor to any wall is found using the following equation Minimum horizontal Vertical distance from the sensor face 10 distance to any wall tothe lowest possible water surface x Tangent Beam angle Table 8 Minimum installation distances from any wall for several ultrasonic beam angles Beam Angle Angle 0 5 m lm 1 5m 2m 2 5m 3m 4m 5m 3 26cm 52cm 79cm 10 5cm 13 1cm 15 7cm 21 0cm 26 2cm 4 35cm 70cm 10 5cm 14 0cm 17 5cm 21 0cm 28 0cm 34 9cm E VI BLS BOS Rd See Te 6 53cm 10 5cm 15 8cm 21 0cm 26 3cm 31 5cm 42 0cm 52 5cm 7 61cm 12 3cm 18 4cm 24 5cm 30 7cm 36 8cm 49 1cm 61 4cm 8 70cm 14 0cm 21 1cm 28 1cm 35 1cm 42 1cm 56 2cm 70 2cm Table 9 Minimum stilling well diameters for several ultrasonic beam angles wall distance x 2 10 cm 05m Im 3 15 2 cm 20 5 cm 25 7 cm 31 0cm 36 2cm 41 4cm 51 9 cm 62 4 cm 4 17 0cm 24 0cm 31 0cm 38 0cm 45 0cm 52 0cm 65 9cm 79 9cm 5 18 7cm 27 5cm 36 2cm 45 0cm 53 7cm 62 5cm 80 0cm 975cm 6 20 5cm 31 0cm 41 5cm 52 0cm 62 6cm 73 1cm 94 1cm 115 1 cm 7s dua icu IURI II LE 8 24 1cm 38 1cm 52 2cm 66 2cm 80 3cm 94 3cm 1224 cm 150 5 cm Maintenance Ultrasonic sensors only require a minimum amount of maintenance Cob
174. ower backup Installation The Sigma 950 is completely sealed even with the door open so wall mount it where convenient If there is any chance of temporary submersion of the datalogger attach 4 inch ID tubing to the bubbler reference and intake ports Route the Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 ends to a safe area and reattach the desiccant cartridges to the tubing with the openings facing downward Cut the submerged end of the bubbler tube at a 45 angle and secure just below the lowest water level that is of interest to monitor Refer to the American Sigma Datalogger section of this report for a step by step quick start for the bubbler sensor Calibration of the bubbler is done at the factory so the settings under MAIN MENU OPTIONS ADVANCED OPTIONS CALIBRATION BUBBER should not be altered unless necessary The bubble rate is preset to 1 second but in extremely dirty water is may be necessary to increase the rate Maintenance Rejuvenate the external desiccant when it turns from blue to pink Remove the silica gel beads from the tube and heat in an oven at 100 C to 180 C 212 F to 350 F until they are blue again Replace the white Hydrophobic filters Part No 3390 in the end of the desiccant tubes as needed The dull side of the membrane must face the airflow The internal desiccant module cannot be recharged by heating and
175. pdf ITRC Report No R 99 002 Figure 5 Control Room Monitoring Computer UPS System g amano Power Volumetric amp RS 232 to 485 Converter Pump Distribution Tank 5 Contactors Box O Va RS 485 Communication an 120 VAC RTU Enclosure 120 VAC 4 PVC Water Supply Line l O OOO Pumps Figure 6 Sensor Testing Setup at the ITRC Water Delivery Facility Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Control Room Inside the control room a UPS provided power to the system computer and RTU panel for 1 hour after a possible power loss The RS 485 communication was fed into a PC running Lookout software Figure 7 with an RS 485 to RS 232 converter Sensor output data were scaled to engineering units with the two water levels used in long term trending as reference points Data was logged to both a comma separated variable CSV file and a Citadel threaded database at an adjustable interval The Human Machine Interface HMI provided by the Lookout software graphically trended all historical data and displayed real time sensor and thermocouple output data Computer pump control could be enabled and disabled from the HMI Figure 7 Lookout software running on the system computer Long term Tre
176. peratures Not recommended for applications where the sensor may be exposed to air Instrumentation Northwest Submersible 800 776 9355 http www inwusa com Power Power Draw Output Advertised Advertised Advertised Lag Overpressure Temp Range Cost Supply amp hr day Accuracy Thermal Resolution Time Rating Error 9 24 0 3 4 20mA 0 1 or 0 2596 2 0 full Infinite None 2x Compensated 479 w 6m VDC full span scale 0 50 C cable desiccant Price includes Sensor 6mof vented polyurethane cable Desiccant tube General The PS9800 allows water to come in contact with the sensing element through four small side holes near the bottom end of the stainless steel sensor housing The stainless steel housing can also contain a temperature sensing element on a separate 4 20 mA loop A desiccant tube is required to keep water from working its way down the vent tube and shorting out the electronics Power Only 9 24 VDC is needed for the PS9800 Some amount a surge protection is standard and an option for lightning protection is available Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Options The lowest gauge pressure range available is 0 5 PSIG 0 3 5 m and the highest is 0 100 PSIG 0 70 m For gauge pressure operation vented cable is required Three cable jacket materials are a
177. pes voltage and current All sensor outputs are in DC not AC Voltage also known as potential is the difference in electric charge between two points similar to water pressure Typical units are volts V or millivolts mV Current is the rate of electricity which flows between two points similar to water flow rate Typical units are amps A or milliamps mA The resistance to electrical current is analogous to friction in pipes Typical units of resistance are ohms Q Resistance depends on temperature conductor material and other factors The following equation one form of Ohm s Law for DC current relates voltage current and resistance Voltage Current x Resistance V IR 2 Main Output Types A common potential output is 0 5 V and the most common current output is 4 20 mA The output is proportional to water level and usually equals 4 mA or 0 V at the lowest readable level and 20 mA or 5 V at the highest readable level Some water level sensors can be purchased with either a V mV or mA output In any Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 case except ratiometric devices the strength of the output signal is proportional to the measured depth or water level While some sensors do not read the water level continuously i e they have some lag time all 4 20 mA and 0 5 V signals are continuous When power i
178. ple uses without complete confusion 4 20 mA readings were within 0 1 full range of the actual current 33 gt oN 5 Eu amp On ci e mo Gc S E SgE 8 88 ein 8E BE e 5 o pos os Bq o a o o 8 9 S c E S28 843 2 2E 5E EBS a S 3 a f g T 2 age ag oe Sh Es S52 3 s B 3 8 amp ag 3 GF 842 gt no an GS O CR500 510 1 2 1 2 7 N CR510 10 4 10 excellent 1 horrible Primary advantages over other dataloggers Fairly wide range of uses for monitoring control and communications Low price Primary disadvantages over other dataloggers Very difficult to use Must be programmed by the user Not easily used with industry standard hardware Coastal Environmental Systems Datalogger 800 488 8291 http www coastalenvironmental com Power Supply Needs External Power Draw Number of Type of Input Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s 10 7 16 VDC or Y 0 1 2 4 depends 16 voltage or 0 5mV to 0 5V 0 05 40 1sec 1 120 240 VAC on settings 8 current many others 70 C day Size Storage Resolution Date Communications Relays Alarms Local Remote List Capacity Time Display Operations Price 26x15x10 2 000 15 to 18 bits Y RS 232 485 amp 422 6 1x0 7A 12VDC Relays N Y 1320 cm 2 000 000 all but 2 input SDI 12 Phone 2x0 15A 12VDC Direct Radio w readings channel
179. ports are configured for one 0 200 mV input one 0 2 5 V input two 0 5 V inputs one 0 10 V input and two 0 25 mA inputs The SmartReader can also be ordered with seven 0 2 5 V ports seven 0 5 V ports or seven 0 25 mA ports Networking and alarm dial out equipment is also available Wiring 10V 10V 10V Common Common Common 4 20 mA Voltage Voltage 5V 5V 5V Transmitter z Transducer Transducer 5V oO SV m 5V oO Gio Common 3 V IN COM SIG Common S EX EX SIG SIG Common Y o o 25V A 25V amp 25V amp 200mV G 200mV G 200mV S le OL 12 OR lt g CL e ig ommon N ommon N ommon yo DC Power DC Power DC Power 25mA 25mA 25mA Source ISHA Source N Source JRA Common Common Common 4 20 mA 3 wire0 5 V 4 wire 0 5 V Figure 58 Three common SmartReader wiring schematics The DC power source must be within the voltage input range for the sensor Installation The logger can be easily mounted on a metal surface with its magnetic backing However it is recommended that the logger be securely mounted or placed on top of a horizontal metal surface A hole i
180. ports pdf WaterLevelSensor pdf ITRC Report No R 99 002 30000 4 25000 20000 raw 32 bit units 15000 10000 Sensor output 5000 0 10 15 20 25 30 35 40 45 50 Actual depth cm Figure 16 Hysteresis problems with the Milltronics Probe Error bars are shown at each data point Separate best fit curves were then applied to the increasing and decreasing data point for each sensor The maximum distance of the output plot from to the line of best fit minus experimental error gave a determination of linearity Figure 17 is a good example of almost no hysteresis but very poor linearity Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 6000 5500 oa e e o AR e e e 4000 Sensor output raw 32 bit units 3500 0 5 10 15 20 25 30 35 40 45 50 Actual depth cm Figure 17 Poor linearity in the Campbell Scientific DB1 Error bars are shown at each point The linearity problems may have been due to the RS 232C to 4 20 mA output converter recommended by the manufacturer Drying Effects Setup The same setup and water levels were used as with long term trending Testing The test tank was drained and allowed to dry for 20 days The tank was then refilled to the high water line Readings were taken from all submersible pressure sensors once per minute before and after the dryin
181. put is to the actual water level Resolution and accuracy improve as the range of the sensor decreases For this reason it is best to purchase a sensor with the smallest range possible for each application If the water level fluctuates by 4 meters a sensor with a 5 meter range would be ideal Communications Protocols A communications protocol is a set of rules and formats which determine the communications behavior of a piece of information It allows for the meaningful exchange of information between certain electronic devices such as a sensor and a datalogger Lehmkuhl 1998 This is the electronic language that devices use to speak to each other The equipment on both ends of the communication must understand the communications protocol INTENSOR PROFIBUS MODBUS SDI 12 and HART are examples Serial Communications Communications protocols require more than a simple 2 wire loop to transfer data A serial communications line such a cable for connecting a personal computer and printer contains several wires and allows for bi directional digital communications data can be transferred both ways The most common serial communications types are RS 232 and RS 485 RS 232 is used to transfer data between two devices such as a printer cable called point to point RS 485 allows for data from many devices to be transferred on a single line called multi drop and can transfer data over much longer distances A 485 to 232 converter cos
182. r of the OWL allows it to be locked in place with a standard padlock Because of its small size it can also be hidden from view The watertight housing reduces the need for an additional enclosure but should be placed in a dry location To configure the OWL in Windows complete the following quick start steps 1 Fit the optical link wand over the optical port on the datalogger or hold it within an inch of the port and connect the other end of the interface cable to a PC 2 Follow the installation instructions on the TrendReader disk label 3 Open TrendReader and from the Communicate menu choose Preferred Logger and OWL Datalogger Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 9 From the Options menu choose Units and DC Current and select MilliAmps for a 4 20 mA input Fora 0 5 V input choose DC Voltage and select Volts If Microsoft Excel will be used for data analysis from Options choose Save as ASCII after Backup and Comma Separated CSV Double click on the COM icon for the port occupied by the interface cable If it is unclear which port the cable is connected to try each icon until the OWL Status window opens Click the Set Up button Set the sample rate and make sure that the correct equation is chosen such as 20mA Current Click on Stop when Full if the OWL should stop taken readings when the memory is full If
183. r other ultrasonic sensors Temperature compensation may be more accurate Primary disadvantages over other ultrasonic sensors Difficult or impossible to use with most dataloggers Separate external temperature sensor required Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Endress Hauser Ultrasonic 800 428 4344 http www endress com Power Supply Power Draw Output Advertised Advertised Lag Time Temp Cost amp hr day Accuracy Resolution Range 18 36 or 12 36 VDC 0 3 2 wire 4 20mA RS 485 1 relay 0 25 full 0 2 cm 0 1 1 seconds 40 585 or 90 127 VAC loop powered 5A 250VAC or 100VDC span depends on sensor 80 C Price includes Sensor General The Endress Hauser Prosonic T is a compact unit that incorporates the sensor and electronics into one unit and has a NEMA 6P rating Four pushbuttons and an optional LCD display provide access to the Endress Hauser operating matrix a distinct operator interface setup The sensor measures water level continuously without any averaging or window emitting 1 10 ultrasonic pulses per second A 4 20 mA loop powered version of the Prosonic T is available for applications with low power requirements Power 12 36 VDC is required to run the Prosonic T 2 wire loop powered versions and 18 36 VDC 90 127 VAC or 180 250 VDC is needed for the 4
184. r within the sensor housing changing the output electrical voltage or current Though the electronics are less complex than in an ultrasonic sensor they still must be mounted directly over the water If the water level fluctuates around a certain level for an extended period of time dithering the potentiometer may wear out quickly Stilling Well A stilling well is absolutely required for float sensors to avoid excess strain on the pulley or spring due to water current and waves High air temperatures can be a problem since the electronics must also be installed within the stilling well Well walls should have about a 5 cm clearance from the float and weights should have adequate clearance USBR 6 14 General Advantages Not affected by dirty water Not affected by water temperature Not affected by foam Low affect of changing air temperatures Low maintenance Low cost Can withstand freezing temperatures No delay between the time when power is first applied and the first output General Disadvantages Stilling well required Cable may slip Pulley and counterweight type only Easily vandalized unless enclosed May wear if water level remains at one position for extended periods Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Salt build up may freeze the pulley Some sensors damaged by flooding
185. rature will drop below 20 C A bubble level is needed to assure vertical installation The beam angle is 5 The buttons marked 4 and 20 located adjacent to the LCD display are used for calibration There are two ways to set the 4 and 20 mA outputs 1 When the water is at the lowest possible level press 4 twice then when at the highest possible level press 20 twice 2 Set the two distances from the sensor face as described in the Adjustments section of the instruction manual If fast response time is more important than resolution set the 4 mA output at the maximum distance possible and the 20 mA at the highest water anticipated water level The blanking distance speed of response to level changes default value and units of measurement can also be set with the keypad Maintenance Only standard maintenance for an ultrasonic sensor is required Test Results The Probe performed about average among the ultrasonic sensors during testing It was significantly affected by air temperature fluctuations but was able to penetrate through foam better than all other ultrasonics except the Badger Meter 2500 Linearity was almost perfect but the Probe had very large hysteresis The hysteresis test range exceeded the sensing range of the Probe which may have resulted in the problems encountered un 5 E 2 n i a 2 2 S a Ez n S a c E un 5 D g OBS amp o s o o amp 8 E oOo ro o of n 5 D D S en Q
186. resis tests came out relatively well It also proved to have excellent long term reliability Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 1 00 70 o 095 50 6 D A E 5 i k o o 5 Q o S 5 pm LL m rma a l 0 90 M 30 0 85 T T T T 7 10 0 10 20 30 40 50 60 Time hours Sensor Air Temperature Figure 37 The improved response over other ultrasonic sensors of the Bailey Fischer amp Porter 50US3000 to fluctuating air temperatures 5 g H j i PRA 2 2 E a EZ ES exl A Ns E o 2 8 8 8 o B 3 als op 9 gt bb galz B e8 2 daBES amp E 3 g ESL uu IRJA AS s S amp S S 3 5 o ons s S a OR v FA jam 8 o 2 2 Og s ES STs e 5 A d jg 2 e a Eu a mA amp S nx o 3 5 E S a 5 o Bg E elg 2 2 8 B B2 2 2 Dals o S amp S 5 o 8 S a 5 5 gt 3 SsSs9 amp 8 S a S o En 8 3 a 2813 33 B S dd 8 a J G Ea s 23 5 o 3 S 5 o i Qa wz E 50US3000 7 8 7 10 JOptiond 4 2 9 10 7 10 AC only 10 7 10 excellent 1 horrible Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period full scale 0 068 0 083 0 040 0 135 0 058 0 067 Max daily error during that 20 day period full scale 0 279 0 110 0 089 0 166 0 107
187. ressor runs on a cycle controlled by a microcomputer Calibration is accomplished with several front panel buttons and an LCD display Before each water level reading is displayed and output the following cycle takes place adapted from www digitalcc com 1 The compressor is turned on for 0 4 seconds to insure that the static pressure in the bubbler tube is the same as the static pressure of the fluid at the bottom of the bubbler tube 2 A one second delay is started after which the compressor is run again for 0 4 seconds Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 3 Aone second delay is started to let the pressure settle after which the pressure is measured several times and averaged to get an accurate pressure reading 4 Step 3 is repeated 3 more times each time averaging the result to obtain a final average bubbler pressure 5 The final average is converted to the required level units only feet or inches can be displayed and sent to the display and the 4 20 mA level transmitter This complex cycle accounts for the minimum 30 second sample time for the BLM but may help to lower the effects of any possible leaks in the system The sample time can be set to a maximum of 64 minutes but if the water level changes by greater than 296 a new compressor cycle is automatically initiated The model 12259 comes standard with a 4 20 mA output loop
188. right hand corner Open Gdhicl if the logger is connected to COMI or open Gdh1c2 if the logger is connected to COM2 If it is uncertain which port is being used open each until there is a connection from the datalogger The unused program can later be deleted Once in the main menu enter 1 to synchronize the logger clock with the computer clock Enter 2 to change the sample interval in minutes Enter 4 to give the site a name Enter 6 to clear the data buffer Enter 7 to read data in a real time mode Water level data 1n feet should read out every second Press any key to return to the main menu To record in meters instead of feet multiply the current slope and y intercept by 0 332 Replace the old values It was found that the user should recalibrate the WL14 prior to installation especially if it will be used for determining flows The following steps describe the recalibration procedure for a sensor with a 3 foot range Do not calibrate the sensor while it is exposed to direct sunlight a Record the factory slope and y intercept settings seen on EZLevel for future reference b Change the y intercept to 0 and the slope to 1 c Place the sensing element which is 1 cm from the tip of the probe exactly 5 cm deep in a container of water A 2 inch PVC pipe makes for a good calibration tube Take several real time readings with EZLevel and average them d Repeat the same step at depths of exactly 40 cm and 85 cm any thr
189. rols and telemetry needed No 4000 per unit acceptable gt 13 bit resolution needed American Sigma sensors only No gt 2 current inputs needed American Sigma 950 Coastal Environmental ZENO 3200 724 000 reading memory size needed Campbell Scientific CRIOX Campbell Scientific CR500 Datalogger sensor unit Datalogger senor unit or independent datalogger Independent datalogger Relays long distance communications or display needed Yes Portable unit needed No Relays long distance No communications No Yes s 7 sensor or display input needed pur Intermountain Intermountain Environmental Padge Mieter Environmental Stevens AxSys SSN 2500 L MPU SmartReader Custom Portable AquaPod The AGM Super Puk is not recommended Because of problems with the attached sensor the Global Water WL14 is not recommended Figure 55 Flowchart for selecting a datalogger for a specific application Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Table 12 Datalogger evaluations external power loss dijsss24442327 som Date time error after S o ua S z S s a amp c a o o a iv Q Datalogger Brand Datalogger Model Simplicity and Correctness of Instructions Requir
190. ross this resistor is what is actually measured Often a datalogger or PLC can be modified to directly read voltage instead of current by removing a single resistor connection from the circuit board Any datalogger that is rated to read voltage signals can be modified externally to read a current signal A 250 O ohm resistor will convert 4 20 mA into a Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 5 V potential if wired as shown in Figure 21 From equation 2 0 004 A x 250 Q 1 V and 0 020 A x 250 OQ 5 V Similarly a 4 20 mA signal can be converted to a 0 5 2 5 V potential with a 125 Q resistor or a 100 500 mV potential with a 25 Q resistor The resistor should be installed at the datalogger so the 0 5 V signal does not have to travel far 4 20 mA Gg Sensor A E Power TUM Source Figure 21 Conversion of a 4 20 mA signal to a 1 5 V signal Datalogger manufacturers will usually supply the correct resistor for reading a 4 20 mA signal but it must be ordered as an option The high quality resistors that must be used to maintain an accurate signal are not easily found in local electronics stores A precision low temperature coefficient 0 196 or lower tolerance resistor should be used Precision resistors can be bought in bulk from mail order c
191. rt No R 99 002 Primary advantages over other ultrasonic sensors User friendly installation and calibration with a portable computer Low cost Primary disadvantages over other ultrasonic sensors 0 5V output only Loses echo easily if not in a stilling well Milltronics Ultrasonic 817 277 3543 http www milltronics com Power Power Draw Output Advertised Advertised Lag Temp Cost Supply amp hr day Accuracy Resolution Time Range 12 28 0 3 4 20mA 1 relay 0 25 0 3 cm 0 8 4 2 40 695 VDC SA 250VAC full scale seconds 60 C Price includes Sensor General The Probe manufactured by Milltronics combines an ultrasonic sensor and all its electronics in a single NEMA 4X unit Calibration is accomplished with a small LCD display and two button keypad located on the top of the sensor itself This display which shows the water level during normal operation is accessible with a flat head screwdriver The Probe can be powered with a simple 2 wire 4 20 mA loop Powering a capacitor prior to each burst produces the ultrasonic pulses The sensor will ignore a reading unless it is received five times in a row which helps to eliminate noise and zeroing An easily programmable window can be set around the output so that any single reading outside this range will be ignored If the window is not used the sensor will read continuously and have basically no lag time
192. s Resolution meters 7 bits 4 Storage Capacity When deciding on a datalogger the user should look at storage capacity in terms of how many readings the logger can store not memory size A datalogger could have a large number of kilobytes k or KB 1000 bytes or megabytes M or MB 1000 k of memory but only be able to hold a small number of readings Number of storable readings is related to bytes by resolution an 8 bit reading takes up 8 bytes of memory A 1 23456 m water level reading then takes up twice as much space as a 1 23 m water level reading Decreasing the sampling interval the length of time between recorded points decreases the time duration over which data can be recorded Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Memory kilobytes x 1000 Storage capacity readings 5 Bits uration Clay See Cin ss toto canoe ity TORRES 6 1440 min day Calibration General Some sensors must be calibrated to output a low current 4 mA or voltage 1 V at the lowest water level that is of interest to monitor and a high current 20 mA or voltage 5 V at the highest water level that is of interest to monitor This is usually done with switches on the sensor circuit board a keypad or a laptop computer The voltage or current range is then scaled to engineering units such as meters or feet by a datalogger or on a comp
193. s Radio Satellite 2x0 2A 5VDC Modem Report software Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Price includes ZENO 3200 ZENOSOFT software General The ZENO 3200 is capable of advanced measurement control data storage and telemetry It has 7 single ended 18 bit analog inputs 15 digital inputs 7 of which are optional outputs and 5 serial communications interfaces Expansion cards are also available for up to 8 analog voltage outputs additional analog inputs or special sensor interfaces Terminal emulation software such as Terminal HyperTerminal CrossTalk Procomm Mirror MacTerminal or Microphone is required but not supplied to interface a PC or Macintosh with the embedded ZENOSOFT firmware which can be confusing Terminal emulation software is provided free with Windows 95 or 98 Separate software is required for analysis of downloaded CSV files Using INTERCEPT PC software prepared for use with ZENO 3200 systems real time data retrieval and graphical analysis are available Power The ZENO requires a 12 VDC 110 VAC or 220 VAC power source Switchable 12 VDC or 5 VDC power can be supplied to sensors A power supply is available from Coastal to plug it into an AC wall socket At 12 VDC the current drain ranges from 3 mA to 100 mA depending on the application and program settings Several standard components prov
194. s are available for the PT420 First the user must specify the full stroke range required the maximum change in water level Different cable tensions can also be ordered Standard tension should usually be sufficient since the float must stay inside a stilling well If extremely turbulent conditions are expected increased cable tension may be needed In the standard setup the measuring cable exits from the top so that the sensor must be mounted upside down on the bottom of a horizontal surface At a higher cost the cable can exit from several other places but a simple L bracket supplied by the user is much cheaper The 20 4 mA output is more convenient than the 4 20 mA output With this option the sensor will output 4 mA at the lowest level and 20 mA at the highest water level the standard with most water level sensors Finally several electrical connections can be ordered from a simple terminal strip to a 6 pin connector If the user will not provide shielded cable the 25 foot instrumentation cable must be ordered The following options are recommended 20 4mA output 25 foot instrumentation cable Installation Beside the construction of a stilling well installation is easy Simply mount the sensor to the underside of a horizontal surface directly over a stilling well and attach a float to the cable The float should be 30 cm in diameter which will reduce errors due Water Level Sensor and Datalogger Testing a
195. s are not recommended for extremely dirty water General Advantages Easy to install Electronics are hidden from view Low power draw Not usually affected by air temperature fluctuations Not affected by foam Almost no time lag No delay between the time when power is first applied and the first output Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 General Disadvantages Damaged by ice Can clog in dirty water Susceptible to malfunction if often allowed to dry May hang up debris Adversely affected by water temperature fluctuations Range is not adjustable Desiccant must be periodically replaced Stilling well often required Lightning protection recommended Damaged if submerged much too deep Easily damaged by aquatic wildlife lt 500 per sensor desired 12 or 24 VDC power supply 24 Druck PTX1830 Instrumentation Northwest PS9800 The Automata LEVEL WATCH and Global Water WL300 sumbersible pressure sensors are not recommended Figure 44 Flowchart for selecting a submersible pressure sensor for a specific application Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Automata Submersible 800 994 0380 http www automata inc com Power Power Dr
196. s com Power Supply Needs External Power Draw Number of Type of Input Accuracy Temp Logging Battery amp hr day Analog Inputs Range Interval s Internal 3 6V 1AH Y 0 00018 1 0 24mA 0 120 1 full 40 0 2 sec lithium battery mV to 0 38 4V scale 85 C 34 min Size Storage Resolution Date Communi Relays Alarms Local Remote List Capacity Time cations Display Operations Price 6x4x9 32 767 8 bit Y Optical None Flashing N N 458 w cm readings data link LED software Price includes OWL 500 datalogger 299 each w o software TrendReader software for Windows Optical interface cable General The ACR OWL datalogger is a compact easy to use device Different models can log either one voltage or one current input The OWL is housed in a water tight enclosure and the optical data link can even transfer data underwater The housing does not have any type of environmental rating such as NEMA and should not be placed underwater ACR s TrendReader software can download data to a PC running Windows The datalogger can be calibrated with the PC software and the data link LED can be configured to blink when an alarm condition is met Power The OWL comes with an internal lithium battery that is guaranteed to last 10 years and is factory replaceable The datalogger however is only guaranteed for 3 years An external battery is required to power the 4 20 mA loop The extern
197. s first supplied ultrasonics and bubblers may take up to a minute to output a reading Submersibles and floats output a signal almost immediately after power up The electronic configurations for the two signal setups are laid out in Figure 20 A milliamp output has proven advantages A voltage output is more susceptible to line noise caused by motors solenoid valves other data lines or other electrical devices Additionally resistance inherent in the data cable causes a loss of voltage signal that is proportional to cable length When the resistance in the datalogger and power source are also taken into account it is apparent that the voltage signal can diminish significantly between the sensor and the location of the signal reading On the other hand current devices supply a constant current regardless of the resistance Therefore sensors with mA outputs are generally preferable The exception is for extremely low power applications of certain dataloggers which is explained later in this report 4 20 mA 4 20 mA 0 5 V 0 5 V Sensor Datalogger Sensor Datalogger m Fd d External External Power Power Figure 20 Two basic sensor setups running on DC power Dataloggers and PLCs only read voltage never current 4 20 mA and other current signals are dropped across a resistor at the datalogger and the voltage potential ac
198. s needed Test Results The LEVEL WATCH was the only submersible pressure sensor to be significantly affected by fluctuating air temperatures due to the use of an air bladder instead of chemical desiccant It also performed poorly during water temperature fluctuations Figure 45 The observed hysteresis was 4 2 a relatively high value The LEVEL WATCH was the first sensor with an intake port that plugged due to sediment in the water Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 80 r 60 78 45 o 5 g 2 o 6 30 E a a o 7 o Viso a iiaii 74 15 72 0 0 15 30 45 60 75 90 Time minutes Sensor Water Temperature Figure 45 Response of the Automata LEVEL WATCH 4 to water temperature fluctuations E BS RB o 2 S 8 JE 8 p 2 9 8 a J Se 82le e I B 8 amp sels Beg E Ealo B 2 3 B B 3 S28 e Ble EB SERA E 7 3 B F 2 Hs OS9 g Eels Balsslg c m o a E B amp A amp EAS S 3 s E 8 gt B Bu gt t o o E Tg gt 3 o Fs L29 Esa onlo nle 2 Es amp m E E 9 Bale mAlS gua g22 z 9 3 S g o 80 6 2 S Sassi m E S s amp e 8 S B EB B p 5 i E g S e JA S g JA d S 5 5 z x o A A LEVEL WATCH 10 7 10 Optional 7 3 1 10 2 9 1 9 7 4 10 excellent 1 horrible Cumulative days 20 40 60 80
199. s pdf WaterLevelSensor pdf ITRC Report No R 99 002 Installation The AGM Super Puk must be mounted in a dry enclosure A standard mounting plate makes installation easy with its four mounting holes To configure the datalogger with no networking capabilities complete the following quick start steps 1 Interface the Super Puk to a PC with a female female RS 232 cable 2 Apply DC power to the PWR terminal ports 3 Insert the program disk and double click on the executable Scada icon There are several Scada icons but in Windows the correct one has an icon that looks like a square with a blue line across the top meant to look like a window Choose F2 To enter the program setup choose F5 Press F5 until the default data handler type reads Super Puk ASCII Download Press F7 then F3 so that the Super Puk date and time will show Press F10 F9 Enter then F10 to save the new settings Press F3 then N If COMI will not be used on the PC press Y instead of N to SQ Oc COMO ON OU m change the communications parameters 10 Press F5 to communicate with the data handler The Super Puk must be prompted to receive a response After each command press Enter 11 To detect a connection type VERS If a one line reply comes up on the screen the Super Puk is connected correctly 12 Type CD to enter the configuration menu The data handler now prompts the user 13 Date Enter the current date as MM DD YY such as 03 13 98 14
200. sient Protection a PCMCIA slot and a 55 70 C temp range Wiring i ANALOG OUTPUTS AND GROUNDS Note resistor across SERIAL DATA POWER AND GROUNDS Analog Input e ZENO 3200 DC Power Source ANALOG SENSOR INPUTS DIGITAL INPUTS AND OUTPUTS ANALOG OUTPUTS AND GROUNDS SERIAL DATA POWER AND GROUNDS ZENO 3200 4 20 mA Transmitter G DC Power Source 0 5 Volt ANALOG SENSOR INPUTS DIGITAL INPUTS AND OUTPUTS Transducer Figure 65 A basic ZENO 3200 wiring schematic With this setup the sensor must be able to handle 12 VDC power With other configurations 12 VDC or 5 VDC can be switched to sensors by the datalogger only when needed Installation The ZENO 3200 must be mounted in a dry enclosure Two mounting holes on the housing allow for easy installation on an enclosure back plate A terminal Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Repor
201. sponse of The Probe at low currents due to capacitor charging close up of Figure 38 Options The available versions of the 3 wire unit are a standard 5 m version an extended range 8 m version and a sanitary version not needed for irrigation use All are programmable for a fault or level alarm and HART Communications Protocol is optional with the 3 wire unit Standard 5 m and intrinsically safe for hazardous areas with a high risk of explosion options are available for the 2 wire loop powered unit No relays are available for the 2 wire version The Probe can come with three 2 inch thread types and several adapters are available for flange mounting A loop powered rate meter can also be ordered if a remote display installed anywhere on the 4 20 mA loop is desired The user must supply all wiring for the sensor The following options are recommended Standard version 2 wire loop powered unless lt 4 second response time and or relays are needed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Installation Easy installation is one of The Probe s main advantages The face of the sensor should be mounted at least 25 cm above the highest anticipated water level with the mounting threads The optional adapter is good for mounting on a plain horizontal surface but a non metal mounting must be used if the ambient tempe
202. spring to produce an upward force on the float cable Figure 40 C Oo Pulley amp Counterweight Spring loaded Figure 40 Two basic float sensor models In the pulley and counterweight version a counterweight provides tension to a beaded cable Notches in the pulley mesh with cable beads forcing the pulley to turn as the water level rises or lowers and the float goes up or down This version of the float sensor is the most difficult to install and calibrate The pulley has a travel stop for both the clockwise and counterclockwise directions During installation the user must ensure that neither travel stop will be hit between the highest and lowest expected positions Additionally the float must be placed on the correct side of the pulley In the second model the cable wraps and unwraps around a spring loaded shaft inside the sensor To install simply hook a float to the cable and lower it to the water If the distance between the highest expected water level and the sensor is more than about 20 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 cm extra cable should be installed between the standard sensor cable and the float instead of purchasing a longer range sensor This will ensure the highest possible resolution across the measurement range Turns of the pulley or spring loaded shaft change the resistance of a potentiomete
203. st Results The Campbell Scientific DB1 did not perform well The output was significantly affected by water temperature Hysteresis was acceptable but linearity was at 92 worse than any other sensor tested A signal converter allowed the RTU panel to read data from the DB1 as suggested by Campbell Scientific This converter may have caused the poor linearity With a stable water level the output normally varied by 0 7 cm and as much as 4 9 cm during over a 2 hour period Long term reliability was low since it was impossible to remotely tell how much nitrogen remained in the bottle and significant drift was experienced The DB1 was not affected by water temperature fluctuations ue en en io E Ee uo nuuc HES 2 ea E 3 3 43 4 gt o g g n gt oa o20 S 5 E S B Is 8 B 32385 s Je EB 3 sals E og i58 E i 2 a amp 3 3 3 ES 8 S 288 PEl PSIE Z Je B B ET oz Z a 20 9 1a A T Ex D A 2 2 cs858 S 5 9 B3E BES S e a J d gt Bs a 5 B E 3 ABA Z D D B 9 5 5 EE 9 mA ls 3 E 953 T 5 Z 2 S E 2 38 Sx ss B d J m 2 Jo z J B g P gB OB z J g B B eS WES ume scm A 2 S 5 b Z o e c DB1 5 1 1 1 1 N 5 10 10 1 1 1 5 2 1 10 excellent 1 horrible Error may have been introduced in the RS 232C to 4 20 mA output conversion Cumulative days 20 40 60 80 100 120 Avg daily error during that 20 day period
204. surement control data storage and telemetry It has 12 single ended voltage or 6 differential current inputs Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 3 analog outputs 8 digital I O ports and 2 pulse counters The user can program it for a very wide variety of uses which can turn out to be a very difficult task The CR10X is designed mainly to read certain specific low power inputs not the more standard 4 20 mA input Power The CR10X requires a single 9 6 to 16 V power supply The same power supply can be used to power 4 20 mA or voltage sensor s only if the voltage is within the voltage input ranges for both the datalogger and the sensor This means that the sensor must typically be able to handle 12 VDC Several power options are available from Campbell Scientific including rechargeable batteries and solar panels Electrostatic discharge protection is provided in the wiring panel and external voltage protection is available for high risk applications Input The CR10X can be programmed to record many types of analog input signals only one of which is a water level sensor Certain sensors are easily programmed for using ShortCut software including the Campbell Double Bubbler and Ultrasonic KPSI Series 169 173 Lundahl DCU 7110 or DCU SDI Druck PDCR900 or PDCR800 Instrumentation Northwest PS9104 PS9105 and PS9104E w o enhanc
205. t No R 99 002 emulation program may be purchased separately or free software built in with Windows 95 and 98 may be used Procomm Plus which was used to interface with the ZENO 3200 programming for this evaluation requires Windows 95 98 or NT 4 0 Procomm Plus can be purchased for about 150 from Quarterdeck at 800 367 5500 or http www quarterdeck com Purchasing over the Internet is often cheaper and other terminal emulation programs are available at lower prices To configure the datalogger for 4 20 mA and 0 5 V sensors over an RS 232 connection complete the following quick start steps For other terminal emulation software besides Procomm Plus steps 5 11 will be different 1 Follow the appropriate wiring schematic in the Wiring section above 2 Connect the ZENO interface cable to the COM3 port on the ZENO 3200 and the other end to a computer Connect a 12 VDC power source to the power terminal ports Install the terminal emulation software on the interface computer Open the Procomm Plus Data Terminal program Under the Options menu choose System Options Modem Connection shops uen des From the Current Modem Connection list choose direct connect Com1 or the correct COM port 8 Click Modem Connection Properties 9 From the Baud rate list choose 9600 Make sure that Parity equals None Data Bits equals 8 and Stop Bits equals 1 Click OK 10 Click Data then Terminal Options 11 From the Curr
206. ta LEVEL 11 13 0 3 4 20mA 0 0 5 0 01 of WATCH VDC 5V 0 1mA span year span C or 0 20mA Druck PTX 9 30 0 3 0 06 0 1 or 0 3 or 0 6 full 1830 VDC 0 100mV_ 0 25 full span span depends on range ITRC Report No R 99 002 esolution Overpressure Temperature List Price D n pb A 9 gt S lt Infinite None NA 40 82 C 485 606 7 depends on range ies i i i id Lo ee ii i di x VDC Infinite None 3x 40 125 C 328 w 6 m cable desiccant replacement Infinite None 6x to 10x Compensated 685 1185 w enclosure depends depends on range accuracy on range Global Water WL300 10 36 0 3 4 20mA 0 2 full Included in Infinite None 4x Compensated 495 VDC span accuracy 2 21 C Instrumentation PS9800 9 24 0 3 4 20mA 0 1 or 0 25 2 0 full scale Infinite None 2x Compensated 479 w 6 m cable desiccant Northwest VDC full span 0 50 C VDC 0 25 0 5 or scale C 1 0 full span Stevens SDT II 12 5 0 3 4 20mA 0 25 full t 0 1 full 35 VDC span scale C Temperature ranges for submersible pressure sensors refer to water temperature Infinite None 1 5x Compensated 778 1 078 w desiccant 6 m 0 50 C cable lightning protection depends on accuracy 52 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Chapter 4 Ultrasonic Sensors O
207. tched sensor power 3 Battery powered with switched sensor power Compact portable pre assembled units can be purchased for certain applications see the Dryden Instrumentation Datalogger Intermountain Environmental AquaPod Datalogger and Intermountain Environmental Custom Portable Datalogger sections of this report Users can also purchase a datalogger sensor battery solar panel and charge controller separately The ACR OWL is a very small self powered datalogger that is good for monitoring a single 4 20 mA input if an 8 bit resolution is acceptable At a sensor range of 2 5 ft about 1 PSI the datalogger has a resolution of 1 100 ft Power Sonic makes sealed rechargeable batteries in a whole range of size which can often be purchased locally Call 650 364 5001 or log on to http www power sonic com to find a nearby distributor or representative Table 1 gives battery sizing suggestions Table 1 Rechargeable battery sizing suggestions for a single 4 20 mA loop powered sensor Amp hour and weight data are for Power Sonic batteries Sensor power Datalogger power Battery replacement Battery amp hours Approximate interval battery we kg Constant Self powered 1 week Constant Self powered 2 weeks Constant Self powered 1 month n Constant Self powered 2 months 26 8 5 Constant Self powered Solar powered 1 2 0 6 Switched External 2 months 1 2 0 6 Switched External 6 months 2 5 1 Sw
208. ted as sensor output versus time Two points were plotted for each date an average high water level reading and an average low water level reading for the entire day Figure 9 Because of problems with algae growth in the rectangular weir plate hole the low water level readings were not taken into account when computing the accuracy for each sensor Accuracy in units of percent full scale output was calculated by dividing Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 maximum offset from the June 1 1998 high water level reading during the testing period by the sensor range A 1 cm drift in a sensor with a 100 cm range yields an accuracy of 1 cm 100 cm x 100 1 120 115 C a a a ee a 4 110 E 6 5 105 2 3 o 9 100 c o o 95 90 85 4 5 25 98 6 14 98 7 4 98 7 24 98 8 13 98 9 2 98 9 22 98 10 12 98 Time days High Water Level Low Water Level Figure 9 Sample long term trending results Data points only show the high and the low water level average outputs for every fourth day Air Temperature Effects Setup In order to test the effects of air temperature fluctuations on the sensors a large canvas tarp was draped over the test tank supported by the sensor shade cover Figure 10 The sensor electronics enclosures were also under the tarp but the RTU panel was left uncovered A standard
209. ten ive E I ied 119 Digital UO BIER a utes ae a a ede uta td uae Dus epa E 122 Tesco BOD DIG 5 ossc actrix tution xL ee i eal 126 Chapter 8 Datalogpersa aede eet Erst sera etia ihr ta ete doce oerte die s 130 VET VI MO n S 130 Datalogger ComparisOns eec en ea Eee t usd deci usoe aee lebe reps DU ue M Cue 133 ACR OWL Datalogger sho ceste NU ie abs dA eae uisa SUR dea tineri 137 ACR S mat Reader DAGlOBBGE i hos mess lea Ga e Puis pa s IPSE ed mid 141 PG MUD Atal OS OOP esc e e easet te ta dace Aaa deis e Re Perd Sala ER AIR UR VERTS 145 American Sigma Datalogger Loi decet See ein in Metas eot rere ghe ede iai png 149 Badger Meter DatalopBer a s one peche dE nU e Ud eate oret s 155 Campbell Scientific CR10X Datalogger esee 159 Campbell Scientific CR500 CR510 Datalogger eene 166 Coastal Environmental Systems Datalogger sees 169 Dryden Instrumentation Datalogger essen 175 Global Water Datalogger suis idt aeter deo tnsei easet acean ta easi rata ded aeneus 176 Intermountain Environmental AquaPod Datalogger sss 181 Intermountain Environmental Custom Portable Datalogger 185 Stevens Datalogger Loan este eae ba gne o nad Roa ese aded pd mia da O 186 Chapter 9 Reverences isin iode Oder onde u etes ea usted Axe Oc RO ede d 192 Vaala N Ape c DE 193 TOSS ALY etas os ae tee D Od coe eor cae d ate
210. the CR10X to bring the accuracy down to 0 25 full scale over the entire 0 40 C compensated temperature range Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Primary advantages over other submersible sensors Lower than average list price Ability to monitor water temperature Primary disadvantages over other submersible sensors Long term drift KPSI Submersible 800 328 3665 http www kpsi com Power Power Draw Output Advertised Advertised Advertised Lag Overpressure Temp Supply amp hr day Accuracy Thermal Error Resolution Time Rating Range 9 30 0 3 0 05 0 1 0 05 full Infinite None 1 5x 778 1 078 w VDC 0 100mV 0 25 0 5 or scale C desiccant 6 m cable 1 0 full lightning protection span depends on accuracy Price includes Sensor 6mofpolyurethane jacketed vented cable Desiccant 4 20 mA lightning protection kit General The KPSI Series 200S and Series 700 are normally constructed of all welded stainless steel but other housing materials are available A large range of options is available for all types of applications Some of the unique options available include internal lighting protection 335 and aneroid bellows 30 a maintenance free alternative to desiccant No wire termination enclosure is needed and a color changing desiccant tube is available
211. the next menu item The up and down arrows are used to edit settings The Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 10 11 12 first press of the up or down key selects the edit mode in which setting can be changed The right arrow enters a submenu if an item is preceded by a gt then there is a submenu for that item or advances to the next character when in edit mode Press MENU until the time setting appears Press up or down once to enter edit mode then use the 3 arrow keys to set the correct time HH MM SS Always press MENU when done altering a setting Press MENU and set the date Once out of edit mode press MENU twice and adjust the logging interval HH MM SS A date and time stamp will not be appended to each reading if the logging interval is less than one minute Once out of edit mode press MENU twice followed by the right arrow to enter the Channel Setup submenu Set Log Usage to ALL unless data should only be recorded above a below a threshold value Proceed through the submenu setting Scale 0 00 has 2 decimals and a 299 99 299 9 range and 0 000 has 3 decimals and a 29 99 29 99 range Warmup set at 00 00 01 4 mA Rd the lowest water level read by the sensor and 20 mA Rd the highest water level read by the sensor Once at gt System Setup in the main menu press the right arrow to enter this
212. those channels Click the Sample Rate box Select the appropriate sample rate and click Accept If the time and date are not correct the PC s internal clock must be adjusted Click Save Setup then OK To view real time readings on your PC click Enable Realtime To download data click the Back Up button in the SmartReader Plus window The datalogger can be configured for a delayed start for configuration away from the measurement site The SmartReader can also be configured to dial a pager caller ID phone when a high or low alarm condition is met on any of the input lines A modem and other special equipment are needed to use this option A network of up to 10 SmartReader loggers can be connected with shielded cable to a single monitoring Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 computer Special equipment is required to run a network including a separate 6 VDC network power supply Data Analysis TrendReader will automatically graph data on a PC in the format of Figure 59 and put data in a table CSV files can also be generated C mA SmartReader Plus Test 18 170 11 5 18 165 10 0 18 160 8 5 Int Temp 25 mA 18 155 7 0 18 150 5 5 18 145 4 0 4 11 30 4 11 40 4 11 50 4 12 00 4 12 10 4 12 20 4 12 30 4 12 40 4 12 50 4 13 00 PM PM PM PM PM PM PM PM PM PM 12 10 98 12 10 98 12 10 98 12 1098 12 10 98 12 10 98 12 1
213. tion transducers The PT8420 up to a 1 5 m range and PT9420 up to a 43 m range meet NEMA 4 standards Primary advantages over other float sensors Easy to install and calibrate Waterproof model available Primary disadvantages over other float sensors Higher cost Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Intermountain Environmental Float 800 948 6236 http www inmtn com Power Power Draw Output Advertised Advertised Lag Temp Cost Supply amp hr day Accuracy Resolution Time Range 4 16 VDC 0 1 0 5V 1 full 0 3 cm None 30 350 scale 50 C Price includes Sensor Float and counterweight General The Intermountain Environmental FP10C is an example of the float pulley and counterweight sensor type displayed in Figure 40 A beaded stainless steel cable runs over a notched pulley One end of the cable to attached to a metal counterweight and the other to a ball float both of which are provided The pulley circumference equals one foot so that each complete rotation of the pulley shaft corresponds to a 1 foot 0 3 m change in water level The pulley shaft is coupled to a potentiometer which changes the resistance in the current loop to produce 0 5 V or 0 2 5 V The FP10C does not have a NEMA rating Power Only a 4 16 VDC excitation is required to take a reading The sens
214. to read from the data port 6 Ifthe computer is connected correctly a menu will appear Type 1 to open a new file 7 Enter a path and filename for the data followed by a ext extension For example enter c filename ext to save directly to the hard drive 8 Enter 0 for the desired offset 9 Type N for the special date time format unless using Lotus 123 for data analysis N for deltas only N for stop on headers and 0 for flow units 10 Once the data has transferred type 2 to close the disk file 11 Type 7 to exit Logterm 12 The data is not saved as a CSV file If using Excel open Excel and then open the filename ext file Instead of choosing delimited as with a CSV file just click Finish Save the file as a Microsoft Excel Workbook do not add an extension to the file name Sumterm ST exe will produce monthly summary reports from raw data ext files In Sumterm type 5 to load new data and enter the name of the raw data file Monthly summary reports can then be printed or saved for further processing in a spreadsheet program Flowterm FT exe produces flow data reports from raw data ext files Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Test Results One the front panel keypad is understood the AxSys MPU is a relatively easy to use datalogger The software is not user friendly even though it does accomplish what is needed Th
215. to the Super Puk for an additional 35 A low power 12V version is available at no additional cost This version uses much less battery power but is harder to work with The two output options for the Super Puk are RS 232 and RS 485 If the dataloggers will be independent units with no networking RS 232 allows for easy connection to a laptop computer Up to 20 Super Puks can be networked on an RS 485 line to a single Genie Puk which is basically an enhanced modem The Genie Puk is a stand alone device no interface computer needed which can auto dial pagers or deliver voice alarm messages over the phone The IPC is a memory module that can store 32 000 128 000 data points for the Super Puk depending on the time and date stamp configuration Wiring Note resistor across Analog Input 0 5 Volt 4 20 mA Transducer Transmitter vaiscousic DC Power DC Power Source Source Figure 60 Two common Super Puk wiring schematics For this wiring setup the 1 Analog PWR 1 Analog Output Input Output l 2 DIN DIN Output 1 2 2 Output 1 2 DC power source must be within the voltage range of both the sensor and the datalogger Water Level Sensor and Datalogger Testing and Demonstration www itrc org report
216. ts about 100 Many sensors dataloggers and computers do not have RS 485 ports For long distance direct data transfer an RS 485 cable with a converter at each end should be used Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Data Storage A Bit About Resolution Datalogger resolution is the smallest change in the sensor output signal that can be recorded by the datalogger The smallest change in water level detected by the datalogger is related to this value but also depends on the span and resolution of the sensor itself To keep datalogger specifications independent of sensors datalogger resolution is reported in bits unrelated to bytes which are a measure of memory size Bits are the number of binary spaces allotted to a single reading Binary numbers consist of zeros and ones only Number of possible combinations of zeros and ones 2 bits 3 An example of a 3 bit binary number is 010 There are 2 8 possible 3 bit binary numbers 000 001 010 100 011 101 110 and 111 A 3 bit datalogger would then have very poor resolution since it could only read 8 different sensor output values If the sensor span equaled 70 cm the datalogger would have a 10 cm resolution 0 10 20 30 40 50 60 70 cm For each increase of one bit the resolution improves 2 fold Typical resolutions are 8 12 16 and 32 bit Total sensor span meter
217. turer use current capable surge protection between the cable and the submersible sensor in addition to the recommended protection in the General Information section of this report Temperature Effects All submersible pressure sensors were negatively affected by changes in water temperature Figure 44 displays a typical example A common delayed response to a rapid temperature change is seen in Figure 44 at around 28 minutes The temperature of the sensing element equilibrates with the water temperature faster than the temperature of the internal electronics does causing a slight delay All submersible pressure sensors are rated for both accuracy and thermal error Both must be taken into consideration when choosing a sensor Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 80 60 78 45 Sensor Output cm N o 69 eo Water Temperature C 74 15 72 0 0 15 30 45 60 75 90 Time minutes Sensor Water Temperature Figure 44 A typical submersible pressure sensor output response to water temperature fluctuations Dirty Water Submersible pressure sensors are more susceptible to clogging from silt and debris than any other water level sensor type Periodic cleaning may be required even in relatively clean water While some manufacturers will provide special nose caps that help to avoid clogging submersible pressure sensor
218. ue of the measurand ASTM 1995 Full scale output algebraic difference between the outputs at the specified upper and lower limits of the range ASTM 1995 Linearity closeness of a calibration curve to a specified straight line ASTM 1995 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Hysteresis maximum difference in output at any measurand value within the specified range when the value is approached first with increasing and then with decreasing measurand ASTM 1995 Measurand physical quantity property or condition that is measured ASTM 1995 Precision closeness of an output value to the measurand value Repeatability ability of a transducer to reproduce output readings when the same measurand value is applied to consecutively under the same conditions and in the same direction ASTM 1995 Resolution smallest change in the measurand value that can be detected 47 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Sensor Comparisons Possible Not Possible 12 stilling well possible Subject to Yes flooding Q Is gt 1000 Yes per sensor No Extremely Yes acceptable dirty water Large water temp fluctuations Foam possible No Solid ice possible Rapid air temp
219. ust be purchased The datalogger is always drawing power but the amount can vary widely When the display is up and running 250 300 mA is being drawn but when the display is out only 1mA is needed If the 950 is run off a battery it must be set to extended power mode so that the display will remain shut down when not in use The bubbler only takes extra power when the compressor is running On the average the compressor draws 800 mA for 2 seconds every 3 minutes while it re pressurizes the internal reservoir Up to two 4 20 mA output ports are optional and must be ordered specifically The 950 must be running on AC power to use a 4 20 mA output No surge protection is available Options Only the options applicable to the bubbler sensor are listed here Please read the Sigma 950 datalogger section for other options As mentioned up to two AC powered 4 20 mA outputs are available Up to for alarm relays can be ordered and a 2400 baud modem is optional For DC power the rechargeable gel battery 135 has a longer life and is cheaper than the Nicad battery 200 If AC power is available order an AC power supply converter AC power backup or a wall mounted battery charger for portable testing For permanent installations where AC power is not available Sigma offers a solar battery charger The following options are recommended 4 20 mA output if needed and AC power is available Rechargeable gel battery or AC p
220. uter running HMI software Low Power Applications General If a very compact low power independent no controls or remote communications water level sensing and datalogging unit is desired there are three main factors which must be considered l Solar power If solar power is not utilized a larger battery must be purchased and replaced or recharged periodically If solar power is used the panel must be placed in a sunny safe location A charge controller must often be used to keep the solar panel from overcharging the battery Switched sensor power More advanced dataloggers have the ability to switch the sensor power on only when a reading is taken Less power is used but dataloggers with this capability Campbell Scientific Coastal Environmental Dryden Instrumentation are normally larger than their simpler counterparts Sensor output A 4 20 mA sensor output should be sufficient for low power applications Some dataloggers may be able to read a ratiometric sensor output where the sensor output voltage depends on the input voltage While this requires an extremely low amount of battery power a programmable datalogger such as the Campbell Scientific must be used Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 The three most highly recommended setups are 1 Solar powered without switched sensor power 2 Battery powered without swi
221. vailable but the HDPE high density polyethylene cable is best suited for permanent irrigation applications HDPE is stiffer and more hydrophobic than PU polyurethane and costs the least of all the available cable materials The FEP cable is only needed when the sensor may come in contact with organic solvents A desiccant chamber is also needed For certain applications a 1 4 NPT nose cone and an M6 cable connector are available As mentioned a 4 20 mA temperature measurement is available as a second channel within the device A 0 196 full scale output maximum accuracy is available on request instead of the standard 0 2596 The following options are recommended Polyurethane vented cable Desiccant chamber Installation Place the sensor tip slightly below the lowest water level that is of interest to monitor Secure the cable to avoid changes in the sensor placement Maintenance The desiccant should be checked every few months and replaced as needed Test Results The PS9800 performed well among submersible pressure transducers A slight drift in output occurred over several months Figure 48 The sensor was not affected by air temperature fluctuations but water temperature fluctuations did change the sensor output significantly Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 120 Tis a on Rr DE E ONERE Ee NORTE ee 1
222. verview General Ultrasonic sensors transmit a series of cone shaped sound waves through the air These sound pulses reflect off the liquid surface and are in turn received by the sensor which measures the time interval between the transmitted and received signal Electronics then convert this time interval into a distance measurement using the speed of sound in air No part of the sensor ever touches the water a distinct advantage of this sensor type Installation The ultrasonic transmitter angle water surface turbidity and distance to the water surface can affect ultrasonic sensor accuracy Ultrasonic sensors have a specified minimum measuring distance called the blanking distance usually 30 45 cm If the water surface rises to within the blanking distance the sensor will not be able to distinguish between a sound transmission and its echo resulting in an unreadable water level see later description However an ultrasonic sensor should be placed as close as possible to the water surface for maximum accuracy It also must be installed absolutely perpendicular to the water in order for the sound waves to reflect directly back to the sensor Figure 32 e L Li al ee 7 Beam 4 Ne d Angle Correct Incorrect Figure 32 Ultrasonic sensor installation Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Finally the sensor must be far en
223. ware and hook up cable Extra cable Installation Installation is very user friendly with the use of the DCU 7110 software A bubble level is required to assure that the sensor is installed vertically The beam angle is 8 so it must be installed a bit farther from any walls than some other sensors Once again use the equation in the overview section to determine this exact distance Once the sensor is installed connect the RS 232 cable to a computer and open the 7110 EXE program Do not disconnect the cable before exiting the program by typing an X If the connection is lost the user must re open the program Close the program reconnect the cable open the program and type X before leaving Ifthis is not done the sensor output will not change no matter what happens to the water level Calibrate the sensor as described in the Sensor Adjustments section of the operator s manual A measuring Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 tape and or staff gauge will be needed Set the offset to the distance from the sensor face to the lowest water level and the span to the distance between the lowest and highest water levels Test Results The Lundahl was the only sensor that lost its echo because of foam on the water surface The default value for a lost echo is equal to value input for the analog span so a control system woul
224. webs and debris should be cleared periodically from the ultrasonic sound path If a stilling well is used dirt can collect on the inside walls and reflect the signal As needed the user should cover the sensor with a plastic bag if it is not submersible and hose down the inside of the stilling well When the electronics are separated from the ultrasonic transmitter by a cable the transmitter is typically waterproof Units that are not separated should usually not be submersed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 Temperature Effects Air temperature as well as radiant heat as from direct sunlight can negatively affect the performance of an ultrasonic The speed of sound through air changes 0 18 for every degree Celsius This means that at a target distance of 2 meters a 25 C change in air temperature throws off the reading by 9 cm 0 0018 x 2m x 25 C 0 09m Most modern ultrasonic sensors come with a built in temperature compensator which measures the air temperature at the sensor and applies a compensating formula to the water level reading The electronics assume that the sound pulses always travel at the same speed which is not true if a temperature gradient exists between the sensor and the water surface If an electronic compensation is used all tested units except the Bailey Fischer amp Porter use a thermistor to monitor temperatur
225. wire versions The sensor has an internal fuse but the customer must supply any surge protection INTENSOR and HART protocol are optional with the 4 20 mA output and several other communications modes are available Options There are several versions of the Prosonic T available including the FMU 230 231 and 232 Table 10 should help determine which model is appropriate for a specific need The Prosonic T FTU 230 and 231 are identical to the corresponding FMU models except that the FTU includes a single high or low point alarm relay For remote operations INTENSOR or HART communications protocols can be ordered and Rackbus RS 485 or Profibus PA serial communication is also available For most models the user can select 2 wire loop DC powered 4 wire DC powered with a separate Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 power supply or AC powered The 2 wire loop powered version draws the least amount of current and only requires 12 36 VDC excitation as opposed to 18 36 VDC excitation for the 4 wire version If the sensor will be located in the sun an optional hood must be ordered or constructed Ordering the mounting bracket or flange and optional LCD display make installation easier Table 10 Applicable options for the Endress Hauser Prosonic T ultrasonic Sensor Model Measuring 2 wire DC 4 wire DC AC Beam Ra
226. y low long term reliability due to the air leak No lag time was apparent due to the continuous reading method of the Reactive Air system 0 95 70 n 0 90 50 ey 2 v E 5 3 E rm e 2 a ina disc E S FE a E S 085 ag 0 80 T T T T T r 10 0 10 20 30 40 50 60 Time hours Sensor Air Temperature Figure 53 A leaking Tesco reactive air monitor during the air temperature fluctuation test The leak is due to incorrect installation by the user The bell purged every 12 hours resulting in the output spikes Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 a on E m q H S 2 o S E E n B Es n faa a Dt 4 S gS amp Ww 2 B En S E 2 o D S e 2 S S6525z 9 L ES 8 a B8BB Z D D 5 55 2a s S 5 2 Be a S a E 2 5 Es S 3 ES uw 5 gA Pel male amp S Ja s J o on S S ow amp o 8ala A T 8 D E E E EB IS l e SERJBEIS l g 2 x S a s eti 2 28 9 B8 IAE 3 g E JF 2o Ps ily 2 D o B a 2 9 9 pP oo oe 9 5 8 gt S E 2 9 5 8 89 z2 85 ee 28 2 18 8 8 P J c MER MU EN ET EE E A B E B 3 R d E e Q D 9 O a A Reactive Air 6 7 9 10 Y 7 7 10 10 9 10 1 NA 8 10 excellent 1 horrible NA not available Cumulative days Avg daily error during that 20 day period full s
227. yden Instrumentation 13 bit Global Water WL14 12 bit Intermountain AquaPod 8 bit Environmental Intermountain Custom 13 bit Environmental portable 458 w software Optical data link Flashing LED None Flashing LED Pager Z Oo 1 148 w software 425 w software RS 232 or RS 485 2 dry contacts 0 5A 28VDC Relays or 0 5A 28VAC RS 232 or Modem Upto4 10A 120VAC or Relays Pager Modem Y 5A 250V AC Report RS 232 or modem 4 1A 24VDC or Relays 0 5A 120VAC lt About 4 000 depends on sensor 2 425 w sensor software HHI i RS 232 modem radio 8 SVDC max 500 Relays pager Optional Y w PC208W 1 410 w PC208W cable satellite modem voice modem software RS 232 485 amp 422 SDI 6 1x0 7A 12VDC 2x0 15A Relays Direct Radio N 1 320 w software 12 Phone Radio Satellite 12VDC 2x0 2A 5VDC Modem Report T iE mE feel T 21 minute RS 232 2 10mA 12VDC Relays Y 1175 w software logging interval 350 w software depends on memory 3500 w sensor battery solar panel datalogger RS 232 modem radio 2 SVDC max 500 Relays pager Optional Y w PC208W 760 w software cable satellite modem voice modem software Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y I mi Y 136 Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 ACR OWL Datalogger 800 663 7845 http www acrsystem
228. ysis Data can be downloaded from the 950 960 using either an RS 232 direct connection or a modem To get recorded data from the 950 960 with a RS 232 connection complete the following quick start steps Insert diskette 1 into drive a and double click on the Install icon Follow the installation instruction 2 Connect the RS 232 interface cable to the 950 960 and the other end to the PC 3 Ifusing a laptop open Laptop Otherwise open Insight If Windows is running a warning signal will come up Click OK to proceed Water Level Sensor and Datalogger Testing and Demonstration www itrc org reports pdf WaterLevelSensor pdf ITRC Report No R 99 002 4 To connect to the 950 960 click on the Flowmeter button in the upper left hand corner Select the correct Port and click OK If it is unclear which port the logger is connected to try one at a time 5 Click Retrieve Logged Data to download To convert data to a CSV file complete the following steps 1 From the Site menu choose ASCII then Site Files 2 Ifthe site file is not listed click Modify then Browse Open the correct folder and click OK then OK again 3 Click on the correct site file Pick the Units and check Level or other appropriate box 4 Click Modify Open the folder where the CSV file should be saved and name the file always followed by txt Click OK 5 Click Create then OK The file will now be saved in a CSV format InSight software has m

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