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Manual-ECH2O-TE-EC-T..

1. ee ee This appendix presents example programs for CSI dataloggers with the hope that the user will be able to take the basic com ponents and apply them to other datalogger types More sam ple programs for are available from the Decagon website and can be found at http www decagon com instruments agdownload html Using with the Campbell Scientific CRIOX Because the probes use digital rather than analog communica tion they require special considerations when connecting to a Campbell Scientific datalogger Explanation To obtain a reading from the ECH O TE or EC TM the datalogger supplies a 0 5 second pulse at 12 V to the probe excitation white wire The ECH O TE outputs the data after 80 ms but the TE is kept on to ensure complete data recep tion After the probe has been read there also must be a delay between excitations to allow the probe to return to its quies cent state we used 5 seconds which is a minimum Note There must be at least a 5 second delay between ECH O TE EC TM excitations This will allow the proces sor to fully rest 29 ECH2O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers All probe excitations can be wired into one Switched 12 V port The probe will output red wire a 0 to 3 V ASCII TTL signal at 1200 baud that will give three numeric values sepa rated by a space and a character Using the P15 command see program example these three val
2. Rockwool Perlite Potting Soil 0 25 VWC Accuracy Mineral soil 3 VWC up to 8 dS m Rockwool 3 VWC 0 5 to 8 dS m Potting Soil 3 VWC 3 to 14 dS m NOTE Electrical conductivities were measured by saturation extract solution EC With a soil specific calibration you can achieve an accuracy of 1 2 VWC for all mineral soils Temperature Range 40 to 50 C Resolution 0 1 C Accuracy 1 C Electrical Conductivity ECH O TE only Range 0 to 50 dS m Bulk Resolution 0 01 dS m from 0 to 10 dS m 0 1 dS m from 0 to 50 dS m Extended EC Range mode Accuracy 10 0 to 6 dS m bulk user calibration required at higher EC Note that the 6 dS m upper limit for the 10 accuracy rep resents a bulk EC not solution EC Even a saline soil with ECH2O TE EC TM Probe Operator s Manual 1 Introduction very high solution EC gt 20 dS m may not have a bulk EC higher than 6 dS m Thus even those who are working in saline soils often will not need bulk EC measurements above 6 dS m Contact Information If you need to contact Decagon e Call us at 509 332 2756 e Fax us at 509 332 5158 e E mail us at echo decagon com Warranty Information All Decagon products have a 30 day satisfaction guarantee and a one year warranty Seller s Liability Seller warrants new equipment of its own manufacture against defective workmanship and materials for a period of one year from date of recei
3. 4 50 C5 TX RX No RTS DTR OS gt 1 14 SE J Start Loc for TX P1_VWC_Ra 6 0 Number of Locs to TX 7 256 Termination Character for RX ECH2O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers 8 50 Max Characters to RX 9 50 Time Out for CTS TX and or RX 0 01 sec units 10 4 Start Loc for RX P2_VWC_RA a Tse als Mult for RX T2350 Offset for RX 7 Do P86 le 53 Set Port 3 Low 8 Excitation with Delay P22 de 1 Ex Channel 2 0 Delay W Ex 0 01 sec units 32 50 Delay After Ex 0 01 sec units 4 0 mV Excitation Repeat process 9 Do P86 1 43 Set Port 3 High 10 Port Serial I O P15 dee Reps Eag 8 Bit TTL ASCII 1200 Baud 2i p TX after CTS 4 60 C6 TX RX No RTS DTR OS gt 1 14 SE Start Loc for TX P1l_VWC_Ra 6 0 Number of Locs to TX Tt 256 Termination Character for RX 8 50 Max Characters to RX Ge 50 Time Out for CTS TX and or RX 0 01 sec units TOS F Start Loc for RX P3_VWC_RA Le Mult for RX T2 9 Offset for RX 11 Do P86 1 53 Set Port 3 Low aaa Excitation with Delay P22 Tec Ex Channel 230 Delay W Ex 0 01 sec units 33 50 Delay After Ex 0 01 sec units 4 0 mV Excitation Repeat process 13 Do P86 Tz 43 Set Port 3 High 14 Port Serial I O P15 Le a Reps EPA 8 Bit TTL ASCII 1200 Baud 3 3 0 TX after CTS 4 70 C7 TX RX No RTS DTR OS gt 1 14 FE L Start Loc for TX P1 _VWC_Ra 6 0 Number of Locs to TX 7 2
4. Communication protocol 27 contact information 4 converting bulk EC to pore EC 17 20 CSI loggers sample program for CR10X 30 using ECH20 TE probes with 29 D DataTrac configuring the ECHO TE in 11 downloading data using ECH20 Utility 25 E ECH20 Utility downloading data 25 Excitation voltage 27 H how the TE works electrical conductivity temperature T 37 ECHO TE Probe Operator s Manual Index volumetric water content 6 installation orientation 10 precautions 9 removing the probe 10 M Multiplexing using the CSI AM16 32 or 416 33 S seller s liability 4 T Temperature how ECH20 TE measures 7 WwW warranty information 4 38
5. M A 2000 A pore water conductivity sensor Soil Sci Soc Am J 64 1922 1925 23 ECH2O TE EC TM Probe Operator s Manual 7 Data Collection amp Analysis 7 Data Collection amp Analysis SESS When using the ECH O TE or EC TM with Em50 loggers data are typically downloaded using the ECH O DataTrac or ECH O Utility programs Following is a description of these programs When using the probes with other loggers e g Campbell Scientific please refer to Appendix A for informa tion on programming Using ECH20 DataTrac ECH O DataTrac is designed for collecting and interpreting data from ECHO dataloggers and probes For information on how to configure a probe and download data using DataTrac please see the DataTrac uset s manual Using ECHO Utility ECH O Utility is the free software that comes with all Em50 and Em5b loggers It enables you to program and configure yout loggers as well as download data in a format that can be used in a spreadsheet program for analysis To use the ECH 0O probes with ECH O Utility you must first configure yout Em50 to read each probe 1 Make sure the probe you will use is properly connected to an Em50 and that the Em50 is connected to your com puter 2 Open ECH O Utility Select the appropriate COM port and click Connect 3 In the Measurement window click on the drop down menu by the port to which your TE is connected and select ECH O TE Moisture Temp EC if using the
6. s Manual 2 How the Probes Work incorrect or erroneous readings Before contacting Decagon about the sensor do the following Datalogger 1 Check to make sure the connections to the data logger are both correct and secure 2 Ensure that your data logger s batteries are not dead or weakened 3 Check the configuration of your probes in ECH O Utility ot ECH O DataTrac to make sure you have selected ECH O TE Moisture Temp EC or EC TM Moi sure Temp under Sensor Type and that you have chosen a calibration equation under the Calibration tab to use with the probes Probes 1 Ensure that your probes are installed according to the Installation section of this manual 2 Check probe cables for nicks or cuts that could cause a malfunction 3 Check your electrical conductivity sensor traces to ensure that they are not tarnished damaged or contaminated If you require additional customer service please contact Decagon at 509 332 2756 or at echo decagon com ECH O TE EC TM Probe Operator s Manual 3 Installing the Probes 3 Installing the Probes SES eee ee Precautions Before you select a site for installation remember that the soil next to the probe surface has the strongest influence on its readings It is important to avoid air gaps or extremely com pact soil around the probe which can skew readings Do not install the ECH O TE or EC TM next to large metal objects which can attenuate
7. 0 10 21 ECH20 TE EC TM Probe Operator s Manual 6 Converting Bulk EC to Pore EC m m the denominator of equation 1 becomes very small leading to large potential errors We recommend that Op not be calculated in soils with VWC lt 0 10 m m using this method Pore Water vs Solution Electrical Conductivity As noted in the previous section pore water electrical conduc tivity can be calculated from bulk EC using the probe mea sured dielectric permittivity of the medium However pore water EC is not the same as solution EC Pore water EC is the electrical conductivity of the water in the pore space of the soil One could measure this directly if the soil was squeezed under high pressure to force water out of the soil matrix and that water was collected and tested for EC Solution EC is the electrical conductivity of pore water removed from a saturated paste In this case the soil is wetted with distilled water until the soil saturates then it is placed on filter paper in a vacuum funnel and suction is applied An electrical conductivity mea surement on the water removed from the sample will give the solution electrical conductivity Theoretically the two are related by the bulk density An example calculation will illus trate this relationship A soil is at 0 1 m m VWC has a pore water EC of 0 7 dS m and a bulk density of 1 5 Mg m We can calculate the solution EC as follows Fe eg ae P 2 65 o 0 0 6 8 _0 7
8. 1200 Baud 0 TX after CTS C4 TX RX No RTS DTR OS gt 1 14 Start Loc for TX P1_VWC_Ra 0 Number of Locs to TX 3 Termination Character for RX DIADHBWNHE a fo 50 Max Characters to RX 9 50 Time Out for CTS TX and or RX 0 01 sec units 10 Start Loc for RX P1_VWC_Ra Tis Mult for RX 12 0 Offset for RX ECH O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers 7 Do P86 Tr Sa Set Port 3 Low 8 End P95 36 ECH O TE EC TM Probe Operator s Manual Declaration of Conformity Declaration of Conformity a EN ECT Application of Council Directive 89 336 EE6 Standards to Which Conformity EN61326 1998 is Declared EN51022 1998 Manufacturer s Name Decagon Devices Inc 2365 NE Hopkins Court Pullman WA 99163 USA Type of Equipment Dielectric soil moisture probe Model Number ECH 0 TE ECH 0 EC TM Year of First Manufacture 2005 This is to certify that the ECH O TE and ECH 0 EC TM dielectric soil moisture probes manufactured by Decagon Devices Inc a corporation based in Pullman Washington USA meet or exceed the standards for CE compliance as per the Council Directives noted above All instruments are built at the factory at Decagon and pertinent testing documentation is freely available for verification 37 ECH20 TE EC TM Probe Operator s Manual Index Index aes C calibration dielectric 16 mineral 14 potting soil 15 soil less media 15
9. The calibration equation generated from these tests is 0 1 087 10 3 Raw 0 629 where is vol water content and Raw is the output of the probe sensors see appendix It is worth noting here that this equation is linear In fact the linear fit provided as good a fit in the mineral soil range as did a higher order polynomial with the added benefit that it is relatively easy to work with in data logger programs etc However one drawback with this 14 ECH O TE EC TM Probe Operator s Manual 4 Probe VWC Calibration approach is that immersed in water this calibration gives a water content of 80 VWC This is because the calibration although linear in the mineral soil water content range we tested 0 to 35 VWC actually is quadratic from 0 to 100 VWC This fact is apparent when calibrating probes in rock wool and other low density material If you want to develop yout own quadratic equation perform a medium specific cali bration or use Decagon s calibration service see http www decagon com echo calibration html Potting Soil The comparatively higher porosity of organic soils like those used for potting plants requires a different calibration equa tion It is interesting to note that the main difference between the calibrations is caused by the high air volume in the organic soils that lowers the starting dry media dielectric of the sen sor The calibration for several potting soils at salinities rang ing
10. follows CR10X AM16 32 C1 gt Res C2 gt Clk T2 V gt 12V G gt G c4 gt Odd L SW 12V gt Odd H Other wiring on the CR10X should be 34 ECH O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers C3 SW 12 V CTRL Table 1 Program oroS Execution Interval seconds Change to meet appli cation Turn on the multiplexer 1 Do P86 1 41 Set Port 1 High Sets the number of times to increment the AM16 32 2 Beginning of Loop P87 dese 0 Delay 24 5 Loop Count Moves the multiplexer to the first channel 3 Do P86 1 72 Pulse Port 2 4 Step Loop Index P90 Le 3 Step Turns on the switched 12V powers up the ECHO TE 5 Do P86 1 43 Set Port 3 High Reads in the serial data from ECHO TE Delays to make sure all data has been delivered The TX RX command 4 can be 40 or 3 It appears that 40 may not work on older dataloggers It should wait 50 ms to receive the data A Any shorter and it will miss the info in 4 The ECHO TE is communicating at 1200 baud R The start location is incremented by 3 each time through the pro gram because the ECHO TE is outputting three numbers each time Please note the double dashed lines in line 10 this must be present or the datalogger will overwrite data from each successive probe into the same 3 input locations 6 Port Serial I O P15 Reps 0 8 Bit TTL ASCII
11. from 0 to gt 8 dS m is given 0 1 04 10 Raw 0 50 Using this equation the output for the ECH O TE EC TM in water will give you 100 VWC Rock Wool The calibration equation for rock wool growing media is O 5 15 107 Raw 1 41 104 Raw 0 160 Other Soil less Media It is not possible to provide calibrations for all growing media We will however try to maintain a database of soil calibra 15 ECH2O TE EC TM Probe Operator s Manual 4 Probe VWC Calibration tions on our website www decagon com which you can use in DataTrac Decagon s graphing software or any spread sheet program to calibrate your sensors If a calibration for your particular growth medium is not in the database you can perform a medium specific calibration or take advantage of Decagon s calibration service see http www deca gon com echo calibration html for more information Note that a medium specific calibration typically results in 1 2 VWC accuracy in your measurements for mineral soil or other growth media Dielectric Calibration The calibration equations given previously were derived from an empirical relationship between probe output and VWC In some specific cases a calibration that gives dielectric permit tivity combined real and imaginary for the ECH O TE or EC TM is useful The following relationship was derived by measuring dielectric with a Campbell Scientific Inc TDR100 and a mini TDR probe and correlating
12. in the soil dominates the total resistance However in a high EC soil the effects of contamination become very large This demonstrates the need to keep the traces clean especially when the probe is to be used in high EC soil Contamination of the gold traces during handling and shipping prevent the 17 ECH2O TE EC TM Probe Operator s Manual 5 Measuring EC with the ECH20 TE factory calibration from being valid past 6 dS m although the probes will measure accurately at much higher EC with proper cleaning and calibration by the user excitation excitation Ringer ming 1 Q R inger print 1 Q Rsoit 100 Q Roi 4 Q gnd gnd Figure 3a Simplified circuit Figure 3b Simplified circuit of contaminated probe in low of contaminated probe in high EC high resistance soil R EC low resistance soil Ryy 101 fingerprint causes 73 fingerprint causes 1 error 25 error Cleaning the Probes 1 Wash the gold traces thoroughly with a drop of Dawn or other grease cutting dish soap and warm water Be sure that the soap doesn t contain skin conditioners or moistur izers 2 Rinse the probe and traces thoroughly with tap water to remove all remnants of soap 3 Dry the gold traces with a clean paper towel Use a scrub bing motion to dry the traces to be sure any particles have been detached Be sure that the paper towel does not have 18 ECH O TE EC TM Probe Operator s Manual 5 Measuring EC with the ECH20 TE a
13. the probes electromagnetic field and dis tort output readings Because the probes have gaps between their prongs it is also important to consider the size of the media you are inserting the probe into It is possible to get sticks bark roots or other material stuck between the probe prongs which will adversely affect readings Finally be careful when inserting the probes into dense soil as the prongs will break if excessive force is used when pushing them in Note The probes were designed to measure VWC in place Although it is possible to use them as a push in probe at several holes it is likely that the gold electrical conductivity array will be damaged by repeated insertion in hard material like sand or dry soil How to Install the Probes The ECH O TE and EC TM can be inserted directly into growing media or soil The tip of each prong has been sharp ened to make it easier to push the probe in Be careful around the sharpened tips The probe needs to be completely covered by soil as shown in Figure 2 ECH2O TE EC TM Probe Operator s Manual 3 Installing the Probes r S wae Figure 2 ECH 0 TE EC TM installed correctly The probes may be difficult to insert into extremely compact or dry soil If you have difficulty inserting the probe try loos ening the soil somewhat or wetting the soil Never pound the probe in Orientation Both probes can be oriented in any direction Because the probes have prongs instead of
14. 0 1 0 Solution EC 0 162 dS m 0 43 22 ECH O TE EC TM Probe Operator s Manual 6 Converting Bulk EC to Pore EC In this example is the porosity p is bulk density p is den sity of the minerals assumed to be 2 65 Mg m subscript d is distilled water and 0 is volumetric water content We assume that the EC of the distilled water is 0 dS m In prac tice solution EC calculated from this method and solution EC taken from a laboratory soil test may not agree well because wetting soil to a saturated paste is very imprecise Converting Bulk EC to Pore EC using ECH20 DataTrac and ECH20 Utility Both the ECH O DataTrac and ECH O Utility programs will display electrical conductivity measurements from the ECH O TE as either bulk or pore water EC The ECH O TE measures bulk EC directly and the conversion described in the previous section is used to calculate pore water EC In ECH O DataTrac you can choose which EC unit to display under Setup gt DataTrac Preferences See DataTrac user manual for more information In the ECH O Utility pro gram you can choose which EC unit to display under Edit gt Preferences If the volumetric water content of the soil is less than 0 10 m m then the software will not perform the con version to solution EC and then no data will be displayed if solution EC is chosen in the preferences Bulk EC will be dis played regardless of volumetric water content Reference Hilhorst
15. 24 ECH O TE EC TM Probe Operator s Manual 7 Data Collection amp Analysis ECH O TE or EC TM Moisture Temperature if using the EC TM If the bulk EC of your soil is likely to exceed 10 dS m then you should choose ECH O TE Extended EC Range available with Em50 firmware version 1 12 or greater 4 Be sure to select an appropriate measurement interval 5 Click Apply to save your settings Next you need to set your preferences for how ECH O Utility performs its data conversion To do this select Edit gt Prefer ences Then configure the preferences for the units in which you wish ECH O Utility to display the ECH O TE Water Content Temperature and Electrical Conductivity data Downloading Data using ECHO Utility After collecting data you download data from the Em50 using ECH 0 Utility 1 Make sure that the Em50 is properly connected to your computer 2 Open ECH O Utility Select the appropriate COM port and click Connect 3 Click on the download Icon 4 Select your preferred data file format see below Data Conversion ECH O Utility has the ability to convert data saved on the Em350 into several formats described below Using the Scan function in DataTrac and ECHO Utility You can take an instantaneous probe reading using the Scan feature in DataTrac and ECH O Utility by simply clicking scan on the main screen Do not scan more than every 5 sec onds or the ECH O TE EC TM processor will not hav
16. 5 Rock Wool ccc cee cece cee eeeeues 15 Other Soil less Media 0 00ee00 15 Dielectric Calibration 00 0e eee 16 5 Measuring EC with the ECH20 TE 17 6 Converting Bulk EC to Pore EC 20 Pore Water vs Solution Electrical Conductivity 22 7 Data Collection amp Analysis 24 Using ECH2O Datel rec nccasercev essa seers s 24 Using ECH2 Uiilit say naw lewgsa een sss 24 Downloading Data using ECH2O Utility 25 Deter Conversion sans vie ya a Dela Bl AA 25 ECH20 TE EC TM Excitation amp Communication e398 ey enews eee See nes 27 Appendix A Using the Probes with CSI Dataloggers ce ee eeees 29 Using with the Campbell Scientific CRIOX 29 EXP CNG OM wih chante ul ahen cohage Wowdds 29 Sample Program for the CRIOX 30 Multiplexing the ECH20 TE EC TM using the AM16 32 or 416 0 0 0 cece cece eee ees 33 Programi EXDIGnGHON isre meran e eaaa 33 Declaration of Conformity 36 ECH O TE EC TM Probe Operator s Manual 1 Introduction 1 Introduction ee l Thank you for choosing Decagon s ECH O TE and EC TM probes for measuring water content temperature and EC This manual is designed to help you understand the probe s features and how to use this device successfully Overview The ECH O TE is designed to measure the water content electrical conductivity and temperature of soil and growing media Using
17. 56 Termination Character for RX 83 550 Max Characters to RX Qi 50 Time Out for CTS TX and or RX 0 01 sec units 10 10 Start Loc for RX P4 VWC_Ra Lil UL Mult for RX ECH O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers 12 0 Offset for RX 15 Do P86 3 53 Set Port 3 Low 16 Excitation with Delay P22 dsp ls Ex Channel 2 0 Delay W Ex 0 01 sec units 33 50 Delay After Ex 0 01 sec units 4 0 mV Excitation Repeat process 17 Do P86 1 43 Set Port 3 High 18 Port Serial I O P15 dese i Reps De 0 8 Bit TTL ASCII 1200 Baud FEP TX after CTS 4 80 C8 TX RX No RTS DTR OS gt 1 14 Bae a Start Loc for TX P1 _VWC_Ra 6 0 Number of Locs to TX 7 256 Termination Character for RX 8 50 Max Characters to RX 9 50 Time Out for CTS TX and or RX 0 01 sec units LO LS Start Loc for RX P5_VWC_Ra Dari Mult for RX 123 0 Offset for RX 19 Do P86 13 53 Set Port 3 Low Multiplexing the ECH O TE EC TM using the AM16 32 or 416 The most effective way to measure large numbers of ECH O TE EC TM probes on non Decagon dataloggers is to use the AM16 32 or 416 multiplexer from Campbell Scientific You can multiplex up to 32 probes on each multiplexer An exam ple CR10X program has been included to help you set up the probes correctly It is written for five probes with the expecta tion that you will modify the program according to your needs Program Explanati
18. ECH O TE EC TM Water Content EC and Temperature Sensors Operators Manual Version 5 DECAGON DEVICES 2007 Decagon Devices Inc All rights reserved Decagon Devices Inc 2365 NE Hopkins Court Pullman WA 99163 1370 05 ECH20 TE EC TM Probe Operator s Manual Table of Contents Contents SSCS l Introduction ces ccd ic ccudisaneeees 1 Overview 0 eee eee teens 1 Specifications annaa naana 2 Contact Information 0 c naaa 4 Warranty Information a a annaua 4 Sellers Liability enssins ennet hes aoe Bin 4 4 2 How the Probes Work 6 Volumetric Water Content 0 5 6 Electrical Conductivity TE only 6 lemperat re Seiten Saris ks ree ie ctere Santa Sg 7 Troubleshooting the Probes 7 Datalogger eee ee eae eet ee aR ae ete neat es ree 8 PROCS 5 egal et E ieee as Ete 8 3 Installing the Probes 9 Precautions 44 sisseds euch eiae ete ieee a tse 9 How to Install the Probes 065 9 Orientations aeree ice dive ke suweeeae beets 10 Removing the Probes 0e eee 10 Making Measurements 0 000ee ee 11 Configuring the Probes in DataTrac i Configuring the Probes with ECH2O Utility 12 4 Probe VWC Calibration 14 Mineral Calibration 00 eee 14 ECH20 TE EC TM Probe Operator s Manual Table of Contents PONG SOI ran Wipe leech Cu a ete Rie 1
19. H O TE Extended 12 ECH O TE EC TM Probe Operator s Manual 3 Installing the Probes EC Range available with Em50 firmware version 1 12 or greater 4 Under the Edit menu select Preferences Configure the preferences for the units in which you wish ECH O Util ity to display the ECH O TE Water Content Tempera ture and Electrical Conductivity or EC IM Water Content and Temperature data 5 Be sure to select an appropriate measurement interval 6 Click Apply to save your settings 13 ECH20 TE EC TM Probe Operator s Manual 4 Probe VWC Calibration 4 Probe VWC Calibration EET The ECH O TE and EC TM have been calibrated in media types including mineral organic and potting soil and rock wool The goal of these calibrations was to create a generic calibration equation that will work in all types of each media with an accuracy of better than 3 volumetric water con tent VWC If you need more accuracy you can perform a media specific calibration to get the accuracy down to 1 2 For more information on how to perform your own soil spe cific calibration or to have Decagon s calibration service per form one for you visit http www decagon com echo calibration html Mineral Calibration The probes were tested in four types of soil sand sandy loam silt loam and clay at solution electrical conductivities of 0 1 to gt 5 dS m and water contents from 0 to 35 volumetric water content VWC
20. a blade like the EC 10 and EC 20 the probe can be placed in any orientation that meets your requirements Removing the Probes When removing either probe do not pull it by the cable This could break the internal wires and cause the probe to malfunc tion or not function at all 10 ECH O TE EC TM Probe Operator s Manual 3 Installing the Probes Making Measurements The ECH O TE and EC TM have been designed to work specifically with the Em50 datalogger To download data to your computer you will need to install ECHO Utility ECH O DataTrac or a terminal port program on your com puter Please see Chapter 6 for more information Configuring the Probes in DataTrac 1 Make sure that the ECH O TE or EC TM is properly connected to an Em50 and that the Em50 is connected to your computer 2 Open the program Select the appropriate COM port and click Connect 3 Double click on your Em50 under New Devices in the left hand Device Directory window 4 Under the Logger tab configure your logger as appro priate 5 Under the Configuration tab in the Sensors section select the Port to which your probe is connected Under Sensor Type Select ECH20 TE Moisture Temp EC if using the ECH O TE probe or Select EC TM Moisture Temp if using the EC TM probe 6 Be sure to set the calibration for your probe under Cali bration tab If you don t no data will be shown in your graph windo
21. an oscillator running at 70 MHz it measures the dielectric permittivity of soil to determine the water content A thermistor in thermal contact with the probe prongs pro vides an average prong temperature while the gold traces on the surface of the sensor form a four probe electrical array to measure electrical conductivity see Figure 1 The ECHO EC TM is the same in design as the ECH O TE and measures water content and temperature The EC TM does not measure electrical conductivity Data from both probes can be read and stored using an Em50 datalogger ECH20 TE EC TM Probe Operator s Manual 1 Introduction Specifications connection cable thermal sensor thermistor 4 probe electrical dielectric VWC array are Only sensor Figure 1 ECH 0 TE EC TM components Dimensions 10cm l x 3 2cm w x 0 7cm d Prong Length 5 2 cm Power requirement 3 15 VDC 0 3 mA quiescent 10 mA for 9 ms measurement Dielectric measurement frequency 70 MHz Output 3 5 mm stereo plug RS 232 or SDI 12 contact Decagon for information on SDI 12 mode Compatibility EM50 Datalogger CSI loggers w serial digi tal I O ECH O TE EC TM Probe Operator s Manual 1 Introduction Calibration Mineral soil rockwool and potting soil supplied in DataTrac Calibrations for other growing media may be available Contact Decagon for information Volumetric water content Range 0 100 VWC Resolution Mineral soil 0 1 VWC
22. e rest and will give only on the screen 25 ECH20 TE EC TM Probe Operator s Manual 7 Data Collection amp Analysis Processed Data File Processed Excel File or Tab Delimited Text File Choosing a processed file type will take the raw data from the Em50 process it and format it into a MS Excel file or tab delimited text file Three data columns are output for each ECH O TE sensor and two for the EC TM The first col umn contains the volumetric water content data and the sec ond contains the temperature data For the TE probe the third column contains the electrical conductivity data The data have units corresponding to the settings chosen in Prefer ences The default mineral calibration is used to calculate volumetric water content from the raw output of probes Raw Data Excel File This file type will take the raw data from the Em50 and for mat it into a MS Excel file Three data columns are output for each ECH O TE sensor and two for the EC TM The first column contains the raw volumetric water content data and the second contains the raw temperature data For the TE probe the third column contains the raw electrical conductiv ity data The data in this raw file format have not been pro cessed into volumetric water content temperature and electrical conductivity This format allows the user to conve niently apply a custom calibration The standard mineral soil potting soil and rock wool vol
23. eater detail the principles behind how the ECH O TE and EC TM operate Volumetric Water Content Both probes use an electromagnetic field to measure the dielectric permittivity of the surrounding medium The probes supply a 70 MHz oscillating wave to the probe prongs that charges according to the dielectric of the material The stored charge is proportional to soil dielectric and soil volumetric water content The ECH O TE EC TM microprocessor measures the charge and outputs a value from the probe Electrical Conductivity TE only Electrical conductivity EC is the ability of a substance to conduct electricity and can be used to infer the amount of polar molecules that are in solution see chapter on EC It is measured by applying an alternating electrical current to two outer electrodes and measuring the voltage between two inner ones Both this voltage and the current are used to determine conductance Conductivity is then derived by multiplying volt age and conductance by the cell constant the ratio of the dis tance of the electrodes to their area The ECH O TE uses a 4 probe array to measure the EC The array is located on the four strips of gold on two of the ECH O TE prongs Care should be taken not to damage the gold surface as doing so could reduce the reliability of the ECH O TE EC TM Probe Operator s Manual 2 How the Probes Work measurement excessive insertion into abrasive material like sand will speed deteriorati
24. it with the output of the probes The dielectric of the medium is given by 7 64 10 Raw 8 85 10 Raw 4 85 10 Raw 10 where Ray is the raw water content output of the probe 16 ECH O TE EC TM Probe Operator s Manual 5 Measuring EC with the ECH20 TE 5 Measuring EC with the ECH O TE ey The ECH O TE uses a gold four electrode array to measure the bulk EC of the surrounding medium The bulk EC mea surement is calibrated at the factory to be within 10 from 0 to 6 dS m This range is adequate for most field green house and nursery applications However some special appli cations in salt affected soils may require measurements with bulk EC greater than the specified range The ECH O TE will measure bulk EC up to at least 50 dS m in the Extended EC Range mode However the user will need to perform a calibration on each probe in the extended range to ensure accurate measurements Contamination on the EC Traces The EC measurement is very sensitive to the presence of non conducting contamination on the gold traces especially at high EC The most common source of contamination is skin oil from handling the gold traces with bare hands Figure 3 a and b show the simplified electrical circuit resulting from a finger print on the gold traces in a low EC soil and high EC soil respectively It is apparent that in a low EC soil the effects of contamination are relatively small because the resis tance
25. ix A Using the Probes with CSI Dataloggers trol port of the Switched 12 V and there were five probes in all that were being measured It is expected that you will modify this pro gram to your individual needs However you should consider the tim ing of this program to be the minimum timing possible to get good probe readings Wiring All white wires 5 in this example wired to SW 12V Channel on 10X Individual red wires for Probe 1 to 5 in C4 to C8 Bare wires to ground Jumper wire from SW 12 V Ctrl to C3 Table 1 Program ake 7 E DWN 01 10 Execution Interval seconds Do P86 43 Set Port 3 High Excites probes with 12 V using SW 12V 2 Port Serial I O P15 Le Reps De 0 8 Bit TTL ASCII 1200 Baud 33 0 TX after CTS 4 40 C4 TX RX No RTS DTR OS gt 1 14 Read probe w Control Port 4 Bs 1 Start Loc for TX P1 _VWC_Ra 6 0 Number of Locs to TX T3256 Termination Character for RX 8 50 Max Characters to RX 9 50 Time Out for CTS TX and or RX 0 01 sec units Ose oT Start Loc for RX P1 _VWC_Ra Tis cL Mult for RX 124p Offset for RX REPEAT PROCESS Do P86 53 Set Port 3 Low Turn excitation to probes off Excitation with Delay P22 Wait 0 5 sec to stabilize J Ex Channel 0 Delay W Ex 0 01 sec units 50 Delay After Ex 0 01 sec units 0 mV Excitation Do P86 43 Set Port 3 High 6 Port Serial I O P15 Led Reps 2720 8 Bit TTL ASCII 1200 Baud 3 0 TX after CTS
26. ny skin conditioners or moisturizers in it as this will undo all of the cleaning that you have just accomplished Be sure not to touch the gold traces with an un gloved hand or to contact them with any source of oil or other non conducting residue 19 ECH20 TE EC TM Probe Operator s Manual 6 Converting Bulk EC to Pore EC 6 Converting Bulk EC to Pore EC For many applications it is advantageous to know the electri cal conductivity of the solution contained in the soil pores Op which is a good indicator of the solute concentration in the soil Traditionally has been obtained by extracting pore water from the soil and measuring 0 directly As one would expect this is a time consuming and labor intensive process The ECH O TE measures the electrical conductivity of the bulk soil surrounding the probes 6 A considerable amount of research has been conducted to determine the relationship between and Op Recent work by Hilhorst 2000 has taken advantage of the linear relationship between the soil bulk dielectric permittivity p and to allow accurate conversion from O to Op if the is known The ECH O TE measures Ep and Op nearly simultaneously in the same soil volume It is therefore well suited to this method The pore water conductivity can be determined from see Hil horst 2000 for derivation 1 iio 6 0 where is the pore water electrical conductivity dS m p is the real p
27. on This program will excite read and collect data from five ECH O TE EC TM probes A wiring explanation is given in 33 ECH20 TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers the text of the program When you wire the multiplexer to the datalogger there are a few things you MUST do First set your multiplexer in 2 x 32 mode using the dip switch on the multiplexer Second wire up all the control ports RES CLD GRD 12V etc exactly as indicated in the text of the program Failure to do this is the primary reason people struggle with multiplexer measurements Third note that you can hook up the SW 12V excitation port H and SE Ch 1 port L to either COM Odd or COM Even ports they are tied together To modify this program to your individual needs simply adjust the loop counts to the number of probes you will be reading on the multiplexer Note This program does not have any output instructions by design Please modify add output instructions to suit your needs Program 7 CR10X Program 1200 BAUD RM1 SETUP PROGRAM csi 7 CR10X Example program to read 5 ECHO TE probes using an AM16 32 The multiplexer is running in 2x32 mode The ECHO TE EC TM has three wires that go to the following on the multiplexer Probe 1 repeat for probes 2 through 5 White gt 1H 2H for probe 2 etc Red gt 1L 2L for probe 2 etc Bare gt Grnd The multiplexer wiring should be as
28. on of the material If the gold sur face appears dull it can be cleaned with a cleanser containing a small amount of grit or pumice Be careful not to contaminate the gold traces with skin oils or other non conducting mate rial Small amounts of oil from skin contact with the gold traces will cause significant inaccuracy in the EC measure ment See Chapter 5 on EC for instructions on cleaning the probes if contamination occurs Temperature The ECH O TE and EC TM use a surface mounted ther mistor to take temperature readings It is located underneath the probe overmold next to one of the prongs Because it is soldered to the copper ground trace on the board it is in ther mal contact with the probe prongs and will read an average temperature along the prong surface Both probes will output temperature in C unless otherwise stated in your preferences file in either the ECH O DataTrac or ECH O Utility pro grams It is important to note that if the black plastic overmold of the probe is in direct sunshine the temperature measurement may read high If your application requires putting the probe over mold in the sun you may want to consider techniques to reduce the radiation load such as shading burying completely in the soil or painting the overmold white Troubleshooting the Probes If you encounter problems with the ECH O TE or EC TM probe they most likely will manifest themselves in the form of ECH20 TE EC TM Probe Operator
29. ortion of the dielectric permittivity of the soil pore water unitless 6 is the bulk electrical conductivity dS m 20 ECH O TE EC TM Probe Operator s Manual 6 Converting Bulk EC to Pore EC which is measured directly by the ECH O TE p is the real portion of the dielectric permittivity of the bulk soil unitless is the real portion of the dielectric permittivity of dry soil unitless amp can be calculated from soil temperature using E 80 3 0 37 Toaig 20 2 where T is the soil temperature C measured by the ECH O TE amp is also measured by the ECH O TE Raw VWC counts can be converted to bulk dielectric by the ECH O TE dielectric calibration E 7 64 108 Raw 8 85 10 gt Raw 4 85 10 Raw 10 3 Finally 9 is an offset term loosely representing the dielectric permittivity of the dry soil Hilhorst 2000 recom mended that p 9 4 1 be used as a generic offset How ever our research in several agricultural soils organic and inorganic growth media indicates that p 9 6 results in more accurate determinations of Oop Hilhorst 2000 offers a simple and easy method for determining for individual soil types which will improve the accuracy of the calculation of P 1n most cases Our testing indicates that the above method for calculating o results in good accuracy 20 in moist soils and other growth media In dry soils where VWC is less than about
30. pt of equipment the results of ordinary wear and tear neglect misuse accident and excessive deterio ration due to corrosion from any cause ate not to be consid ered a defect but Seller s liability for defective parts shall in no event exceed the furnishing of replacement parts FO B the factory where originally manufactured Material and equip ment covered hereby which is not manufactured by Seller shall be covered only by the warranty of its manufacturer Seller shall not be liable to Buyer for loss damage or injuries to per sons including death or to property or things of whatsoever kind including but not without limitation loss of anticipated profits occasioned by or arising out of the installation opera tion use misuse nonuse repair or replacement of said mate rial and equipment or out of the use of any method or ECH O TE EC TM Probe Operator s Manual 1 Introduction process for which the same may be employed The use of this equipment constitutes Buyer s acceptance of the terms set forth in this warranty There are no understandings represen tations or warranties of any kind express implied statutory or otherwise including but without limitation the implied warranties of merchantability and fitness for a particular pur pose not expressly set forth herein ECH20 TE EC TM Probe Operator s Manual 2 How the Probes Work 2 How the Probes Work SS EE The following paragraphs will explain in gr
31. te wire is Ex citation the connector base shield is ground and the inter mediate ring red wire is Serial Out voltage The ECH O TE can be excited by any voltage 3 and 15 V It also features reverse polarity protection however care should be taken not to hook it up backwards 27 ECH2O TE EC TM Probe Operator s Manual 7 Data Collection amp Analysis The serial out is 1200 baud asynchronous CMOS with 3 volt levels Each data byte consists of a start bit low 8 data bits least significant bit first and a stop bit high The first byte is transmitted 50 ms after excitation Three numbers are trans mitted the dielectric output the electrical conductivity output and the temperature output The electrical conductivity output of the TM is always 0 Power must be removed and reapplied for it to read and transmit again The first number is the dielectric output It is related to water content by the user through calibration The second number is electrical conductivity in mS m The electrical conductivity output of the TM is always 0 Divide this number by 100 to get dS m This value is already temperature corrected within the TE probe The final number is 10 T 400 where T is the Cel sius temperature To convert it to temperature subtract 400 and divide by 10 28 ECH O TE EC TM Probe Operator s Manual Appendix A Using the Probes with CSI Dataloggers Appendix A Using the Probes with CSI Dataloggers E
32. u metric water content calibrations can be found in Chapter 4 of this manual Probe VWC Calibration A soil specific calibra tion can also be applied here For information on developing soil specific calibrations visit http www decagon com echo calibration html 26 ECH 0O TE EC TM Probe Operator s Manual 7 Data Collection amp Analysis For the ECH O TE the raw electrical conductivity data are the temperature corrected soil bulk electrical conductivity in mS m To convert to more standard units of dS m divide by 100 If you are using the ECH O TE Extended Range mode divide by 10 to convert EC values to dS m See Chapter 6 Converting Bulk EC to Pore EC for information on convert ing the bulk EC values to pore EC values The raw temperature data can be converted to temperature in degrees C by dividing by 10 and subtracting 40 DataTrac File When the DataTrac file format dxd is downloaded a single 10 digit number is downloaded for each sensor The dxd for mat is easily imported into Decagon s convenient DataTrac graphing software It also has the advantage that it can be con verted with ECH O Utility to the other file formats listed above See the manual for your Em50 datalogger for details on how to do this ECH4O TE EC TM Excitation amp Com munication The ECH O TE EC TM connects through a 3 wite cable with a stereo connector The three connections are Excitation Ground and Serial Out The connector tip whi
33. ues will automatically be read into three successive input locations on the datalogger Once they have been collected they must be moved to another input location or into final storage if you would like them to be saved not done in the program The probes each have a three wire interface which comes in two varieties a 3 conductor 3 5 mm stereo plug and a blunt cable with three bare wires If you have the 3 5 mm stereo plug you need to either cut off the plug and strip the wires or purchase a probe adapter pigtail from Decagon The plug is wired with the tip as excitation ring middle conductor as output and the sleeve bottom conductor as ground The probes must be wired with the all white excitation wires connected to the Switched SW 12 V excitation red wires connected to individual control ports starting at C4 bare wires connected to ground and a jumper wire from C3 to SW 12V Ctrl port To convert raw data to values of water content EC and tem perature refer to chapters 4 and 5 Please note that although the TM will output three parameters the EC will always be 0 Sample Program for the CRIOX Program ECHO TE EC TM CR10X Measurement csi 7 CR10X This program is an example of how to hook up ECHO TE EC TM probes to the CR10X datalogger This was written to leave Control Ports 1 and 72 Cl amp C2 free for other control purposes C3 is wired to the Con 30 ECH O TE EC TM Probe Operator s Manual Append
34. w Choose the calibration appropriate for your growing medium or soil These calibration equations were derived from material obtained at the factory If a 11 ECH2O TE EC TM Probe Operator s Manual 3 Installing the Probes more precise calibration is desired you should follow directions found in http www decagon com app notes echocal pdf You can also ask about Decagon s custom calibration service You can alter other settings as well such as the graph line color axis range etc Click OK to make the settings per manent Once you have exited back to Chart View click Down load After all information has finished processing the computer will automatically update the chart or table applying any color or line settings you have made Note You can also use a terminal port program to take read ings Please refer to Appendix A for instructions as well as explanations of the types of readings Configuring the Probes with ECH O Utility t Make sure the ECH O TE or EC TM is properly con nected to an Em50 and that the Em50 is connected to your computer Open ECH O Utility Select the appropriate COM port and click Connect In the Measurement window click on the drop down menu by the port to which your ECH O TE EC TM is connected and select ECH O TE Moisture Temp EC if using the TE or EC TM Moisture Temp if using the EC TM If the bulk EC of your soil is likely to exceed 10 dS m then you should choose EC

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