10HS Manual - ICT International
Contents
1. where R is the series resistance V is voltage at time 4 V is the starting voltage and Vis the applied or supply volt age Further for a capacitor with a geometrical factor of E the capacitance is related to the dielectric permittiv ity of the medium between the capacitor electrodes by C 8 F 2 where is the permittivity of free space Thus the amp of the soil can be determined by measuring the change time 1 of a sensor buried in the soil Conseguently as water has a dielectric permittivity that is much greater than soil minerals or air the charge time t in the soil of Eq 1 can be correlated with soil volumetric water content 10HS Soil Moisture Sensor 4 Installing the Sensor 4 Installing the Sensor When selecting a site for installation it is important to remem ber that the soil adjacent to the sensor surface has the strongest influence on the sensor reading and that the sensor measures the volumetric water content of the soil Therefore any air gaps or excessive soil compaction around the sensor and in between the sensor prongs can profoundly influence the readings Also do not install the sensors adjacent to large metal objects such as metal poles or stakes This can attenuate the sensor s electromagnetic field and adversely affect readings In addition the 10HS sen sor should not be installed within 5 cm of the soil surface or the sensing volume of the electromagnetic field can extend out2. Apparent dielectric permittivity 1 air to 50 Soil volumetric water content VWC 0 0 57 m3 m3 0 57 VWC Accuracy 0 5 from of 2 to 10 2 5 from of 10 to 50 VWC VWC Using standard calibration equation 0 03 m m 3 VWC typical in mineral soils that have solution electrical conductivity lt 10 dS m Using soil specific calibration 0 02 m m 2 VWC in any soil Resolution 0 1 from of 1 to 30 0 2 from of 30 to 50 VWC 0 0008 m3 m3 0 08 VWC in mineral soils from 0 to 0 50 m3 m 0 50 VWC Measurement Time 10 ms milliseconds Power requirements 3VDC 12mA to 15 VDC 15 mA Output 300 1250 mV independent of excitation voltage Operating Temperature 0 50 C Survival Temperature 40 to 50 C 1 10HS Soil Moisture Sensor 1 Introduction Connector types 3 5 mm stereo plug or stripped and tinned leads Cable length 5 m standard custom cable length available upon request Datalogger Compatibility non exclusive Decagon Em50 Em50R Em5b ProCheck handheld reader Campbell Scientific CR10X 21X 23X CR850 1000 3000 etc Other Any data acquisition system capable of switched 3 tol5 V excitation and single ended voltage measurement at 12 bit or better resolution Customer Support If you ever need assistance with your 10HS or if you just have questions or feedback there are several ways to contact us NOTE If you purcha
3. Number 10HS Year of First Manufacture 2008 This is to certify that the 10HS dielectric soil moisture sensors 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 instru ments are built at the factory at Decagon and pertinent testing documentation is freely available for verification 17 10HS Soil Moisture Sensor Index Index A Accuracy 1 Alternate connection methods 10 B Background 4 C Cable length 2 Calibration 12 Calibration service 12 Campbell Scientific 8 Capacitance technique 5 Compatibility 2 Connector types 2 Customer Support 2 D Datalogger connections 10 Dielectric permittivity 5 Duration 8 E ECH20 Utility 8 Edlog 13 Electromagnetic field 6 F Fax 3 Frequency 4 I Installation horizontal 6 vertical 7 Introduction 1 18 10HS Soil Moisture Sensor Index L Liability 3 M Measurement Time 1 Mineral soil calibration 11 O Operating Temperature 1 Orientation 7 Output 1 P Particle size 6 Phone 2 Power reguirements 1 Programs 13 R Range 1 Removing the sensor 7 Resolution 1 S Sample programs 13 Specifications 1 Stereo plug 9 Survival Temperature 1 T Theory 5 W Warranty 3 Wiring configuration 9 19
4. of soils the accuracy of the VWC measure ment can be poor despite an accurate measurement of dielectric permittivity Some examples of this are highly compacted soils very low bulk density soils soils with abnormally high organic matter content and soils with high dielectric mineral composi tion e g TiO2 sands Additionally the accuracy of the 10HS may suffer in soils with very high electrical conductivity gt 10 dS m solution EC In these soils it may be necessary to calibrate the 10HS to your specific soil type With a soil specific calibra tion the accuracy of the VWC measurement will be improved to 1 2 in any soil or other porous medium If you are interested in a soil specific calibration for your 10HS there are two options available You can create your own sensor calibration by following the directions in our application note titled Calibrating ECH O soil moisture probes from the Decagon website www decagon com and following the step by step instructions for calibrating your soil moisture sensors Since some users do not have the time or eguipment to conduct their own calibration Decagon now of fers a service providing soil specific calibrations to our customers This calibration service also applies to non soil materials such as compost potting materials etc Contact Decagon for more informa tion on this service sales decagon com 12 10HS Soil Moisture Sensor 7 Sample Programs 7 Sample Programs The
5. of the soil and reduce accuracy Because the 10HS has gaps be tween its prongs it is also important to consider the particle size of the medium you are inserting the sensor into It is possible to get sticks bark roots or other material stuck between the sen sor prongs which will adversely affect readings Finally be care ful when inserting the sensors into dense soil as the prongs can break if excessive sideways force is used when pushing them in Procedure When installing the 10HS it is imperative to maximize contact between the sensor and soil For most accurate results the sen sor should be inserted into undisturbed soil There are two basic methods to accomplish a high quality installation Method 1 Horizontal Installation Excavate a hole or trench a few centimeters deeper than the depth at which the sensor is to be installed At the installation depth shave off some soil from the vertical soil face exposing undisturbed soil Insert the sensor into the undisturbed soil face until the entire sensing portion of the 10HS is inserted The tip of each prong has been sharpened to make it 6 10HS Soil Moisture Sensor 4 Installing the Sensor easier to push the sensor in be careful with the sharp tips Backfill the trench taking care to pack the soil back to natural bulk density around the black plastic portion of the 10HS Method 2 Vertical Installation Auger a 4 inch hole to the depth at which the sensor is to be insta
6. 10HS Soil Moisture Sensor QO am SE re 33 UOSNIS JUNISIOW SHOL Operator s Manual Version 3 Decagon Devices Inc 2365 NE Hopkins Court Pullman WA 99163 509 332 2756 fax 509 332 5158 www decagon com Trademarks 10HS is a registered trademark of Decagon Devices Inc 2008 2010 Decagon Devices Inc 1 Introductions issnin 1 SpeciNCAtIONS sun soereiuieiwerses niiair iiini 1 C stomer SUD POLE maassaan Kam av sv kv tte s 2 Warranty Tatormatton vuan masa 3 Sellers Liability amstmm aims vi astmaa Sak hms ni S n 3 2 About 0 itua 4 Background Ki eee eee eet Rem oma uomaa Tati 4 Di IN OU A sae 5 4 Installing the SensOrsitsisseieccousesastacseceeiaaaes 6 Colletti Datinmessasssut um eseo a 8 Data logger Rogulkooehtsimussomusvuyuehie sa Ot 8 De AZ all A KAI aasin assa massan niva aa mn 11 Dielectric calibration ovavem s v soek s jo j n 11 Mineral Soil alibratiom s u visa pndieaamsssaa 11 Te Sample Prop tamis sarvensa massan 13 Declaration of Conformity veasssmvsssassaa ss 17 Table of Contents 10HS Soil Moisture Sensor 1 Introduction 1 Introduction Thank you for choosing the 10HS soil water content sensor This in novative sensor will enable you to monitor volumetric water content of soil accurately and affordably This manual is designed to help you understand the sensors features and how to use this device success fully Specifications Range
7. C1 high to pull SW 12 port high 1 Do P86 1 41 Set Port 1 High delay program 10 ms and measure SE channel 1 in units of volts 14 10HS Soil Moisture Sensor 7 Sample Programs ve 2 Excite Delay SE P4 1 1 Reps 255 2500 mV Slow Range SE Channel 4 1 Excite all reps w Exchan 1 5 1 Delay 0 01 sec units 6 0000 mV Excitation 7 1 Loc ten_HS_V 8 001 Multiplier 9 0 0 Offset sturn off excitaiton 3 Do P86 1 51 Set Port 1 Low sapply calibration updated 8 09 we Polynomial P55 1 Reps 1 X Loc ten HS V 2 F X Loc VWC 1 92 CO 16 69 Cl 707 002 2 97 C3 0 0 C4 0 0 C5 O 04 AU KW D An If time is P92 0000 Minutes Seconds into a 60 Interval same units as above 10 Set Output Flag High Flag 0 WN 15 10HS Soil Moisture Sensor 7 Sample Programs 6 Real Time P77 18390 1 1110 Year Day Hour Minute midnight 0000 7 Average P71 12836 1 1 Reps 22 Loc VWC Table 2 Program 02 0 0000 Execution Interval seconds Table 3 Subroutines End Program 16 10HS Soil Moisture Sensor Declaration of Conformity Declaration of Conformity 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 Sensor Model
8. age or injuries to persons 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 operation use misuse nonuse repair or replacement of said ma terial and equipment or out of the use of any method or process for which the same may be employed The use of this equipment constitutes Buyer s acceptance of the terms set forth in this war ranty There are no understandings representations or warranties of any kind express implied statutory or otherwise including but without limitation the implied warranties of merchantability and fitness for a particular purpose not expressly set forth herein 10HS Soil Moisture Sensor 2 About the 10HS 2 About the 1OHS The 10HS measures the dielectric constant of the soil in order to find its volumetric water content VWC Since the dielec tric constant of water is much higher than that of air or soil minerals the dielectric constant of the soil is a sensitive mea sure of volumetric water content The 10HS has a low power requirement and very high resolution This gives you the abil ity to make as many measurements as you want i e hour ly over a long period of time with minimal battery usage Background Info In 2005 the Decagon research team optimized a sensor oscillator fre quency for very high accuracy soil moisture measurements The first sen so
9. following programs are examples that can be used with dataloggers from Campbell Scientific The first program is for a CR1000 data logger but can be easily adapted for other CRBa sic type loggers The second program is for a CR10X data logger but can be easily adapted to other Edlog type loggers Note that the 10HS needs 3 15 V DC excitation and therefore cannot be excited with the 2 5 V excitation port of many Campbell Scien tific data loggers We recommend that the switched 12V or CAO port be used to excite the 10HS CR Basic type datalogger CR1000 Series Datalogger program to read one Decagon 10HS sensor wiring white SW 12 red SE CH1 bare gnd Public tenHSmV VWC DataTable Table1 1 1 Datalnterval 0 60 Min 10 Average 1 VWC FP2 False EndTable BeginProg Scan 10 Sec 0 0 SW12 1 Delay 0 10 mSec 13 10HS Soil Moisture Sensor 7 Sample Programs VoltSe ten HSmV 1 mV2500 1 1 0 60Hz 1 0 0 SW12 0 VWC 2 97e 9 tenHSmV43 7 37e 6 tenHSmV2 6 69e 3 tenHSmV 1 92 mineral soil calibra tion updated 8 09 CallTable Table1 NextScan EndProg Edlog type data logger CR10X program to read 10HS sensor with CR10X wiring Jumper from C1 to SW 12V CTRL C1 is used to turn on the switched 12V port 10HS white excitaiton SW 12V 10HS red Vout SE CH1 10HS bare gnd G or AG Table 1 Program 01 10 Execution Interval seconds set
10. l connections and make the sensor unusable 10HS Soil Moisture Sensor 5 Collecting Data 5 Collecting Data Data logger Requirements The 10HS is designed to work most efficiently with Decagon s Em50 Em50R or EM5b data loggers or our ProCheck handheld readout They can however be adapted for use with other data loggers such as those from Campbell Scientific Inc for example The 10HS requires an excitation voltage in the range of 3 to 15V It produces an output voltage that is related to the volumetric water content of the soil in which it is buried and ranges be tween approximately 0 3 to 1 25V The output of the 10HS is independent of the excitation voltage between 3 and 15V Any datalogger which can produce a 3 to 15V excitation with ap proximately 10 millisecond duration and read a volt level signal with 12 bit or better resolution should be compatible with the 10HS The current requirement for the 10HS is less than 15mA Note The 10HS is intended only for use with dataloggers and read out devices which can provide short excitation pulses leaving the sensor turned off most of the time Continuous excitation not only wastes battery power but may under certain circumstances cause the sensor to exceed government specified limits on electromagnetic emissions Using the 10HS with Em50 Em50R and Em5b data loggers The 10HS is designed for very easy integration into the Em50 EM50R and Em5b based data logging systems Si
11. lled Insert the sensor into the undisturbed soil at the bottom of the auger hole using your hand or any other implement that will guide the sensor into the soil at the bottom of the hole Many people have used a simple piece of PVC pipe with a notch cut in the end for the sensor to sit in with the sensor cable routed inside the pipe After inserting the sensor remove the installation device and backfill the hole taking care to pack the soil back to natural bulk density while not damaging the black plastic portion of the sensor or the sensor cable in the process With either of these methods the sensor may still be difficult to insert into extremely compact or dry soil Never pound the sensor into the soil If you have difficulty inserting the sensor you may need to wet the soil This will obviously re sult in inaccurate VWC measurements until the water add ed during installation redistributes into the surrounding soil Orientation The sensor can be oriented in any direction However orienting the flat side perpendicular to the surface of the soil will minimize effects on downward water movement Keep in mind that the sensor measures the average VWC along its length so a vertical installation will integrate VWC over a 10 cm depth while a hori zontal orientation will measure VWC at a more discrete depth Removing the Sensor When removing the sensor from the soil do not pull it out of the soil by the cable Doing so may break interna
12. mply plug the stereo plug into one of the five ports on the Em50 Em50R or Em5b use ECH O Utility ECH O Utility Mobile or Data Trac software to configure that port for a 10HS see respec 10HS Soil Moisture Sensor 5 Collecting Data tive manuals and set a measurement interval for the log ger For more detailed instructions on configuring the data logger consult your Em50 Em50R or Em5b user manual 3 5mm Stereo Plug 3 5mm Stereo Wiring 10HS sensors used with Decagon loggers come with a 3 5mm stereo plug connector The stereo plug allows for rapid con nection directly to Decagon s Em50 Em50R and Em5b data loggers and to the hand held ProCheck readers Below is a di agram showing the wiring configuration for this connector Analog a 11 Ground Excitation Connecting to a non Decagon Data logger 10HS sensors for use with non Decagon data loggers come pre configured with stripped and tinned lead wires at the customer s request Analog out Red Ground Bare Excitation White 10HS sensors with the stripped and tinned cable option can be made with custom cable lengths up to 250 ft on a per foot fee basis This option gets around the need for splicing wire a pos sible failure point 10HS Soil Moisture Sensor 5 Collecting Data Connect the wires to the data logger as shown with the supply wire white connected to the excitation the analog out wire red to an analog input and the bare ground
13. on above With Decagon s Em50 Em50R Em5B and ProCheck readers the following standard calibration function can be applied E 7 449 X 101 raw counts 1 969 X 10 7 raw counts 1 890X 104 raw counts 6 691 X 10 raw counts 7 457 With non Decagon data acquisition equipment the following calibration can be applied Note that this calibration function is valid for any sensor excitation between 3 and 15 V DC 6 2 589 X 107 mV 5 010X 107 mV 3 523 X 104 mV 9 135 X 10 mV 7 457 Mineral Soil Calibration For convenience Decagon has also developed a standard calibra tion equation for mineral soils to be used with the 10HS With this standard calibration equation and careful sensor installation accuracy of better than 3 VWC 0 03 m m is possible with most mineral soils In these soils it is generally not necessary to calibrate the 10HS for your particular soil type and the standard mineral calibration below can be used 11 10HS Soil Moisture Sensor 6 Calibration Em50 Em50R Em5B and ProCheck VWC m m3 1 17 X 10 raw counts 3 95 X 10 raw counts 4 90 X 10 raw counts 1 92 With non Decagon data acquisition equipment the following calibration can be applied Note that this calibration function is valid for any sensor excitation between 3 and 15 V DC VWC m m 2 97 X 10 mV 7 37 X 10 mV 6 69 X 103 mV 1 92 Due to the complexity
14. r to incorporate the new frequency was our EC 5 sensor It quickly became the most popular soil moisture sensor we ve designed The new 10HS sensor uses the same 70MHz oscillator frequency as the EC 5 but has a larger soil volume and requires no special calibration when used with other systems New features of the 10HS include Onboard voltage regulator allowing you to power the sensor with a wide range of excitation voltages 3 15 VDC without changing the calibration Large sensing 1100 cubic centimeters allowing you to have a more representative measurement of soil VWC The 10HS sensor runs at the same oscillator frequency that has given the EC 5 exceptional performance in soils Kizito et al 2008 Bogena et al 2007 We recommend the 10HS sensor for mineral soil applications wheresoilheterogeneityisaconcern However wecontinuetorecommend the smaller EC 5 sensor for soilless substrate applications or applications where VWC measurements on smaller scales e g near surface measure ments laboratory column studies greenhouse applications are desired 4 10HS Soil Moisture Sensor 3 Theory 3 Theory The 10HS sensor measures the volumetric water content of the soil using a capacitance technique By rapidly charg ing and discharging a positive and ground electrode capaci tor in the soil an electromagnetic field is generated whose charge time t is related to the capacitance C of the soil by V V t RCln Jk 1
15. sed your 10HS through a distributor please contact them for assistance E mail support decagon com Please include your name contact information instrument serial number s and a description of your problem or question sales decagon com Please include your name address phone number the items you wish to order and a purchase order number Credit card numbers should always be called in Phone 1 800 755 2751 USA and Canada Only 1 509 332 2756 International Our Customer Support and Sales Representatives are available Monday thru Friday from 8am to 5pm Pacific Standard Time 10HS Soil Moisture Sensor 1 Introduction Fax 1 509 332 5158 Warranty Information The 10HS sensors have a 30 day satisfaction guarantee and a one year warranty Seller s Liability Seller warrants new equipment of its own manufacture against de fective workmanship and materials for a period of one year from date of receipt of equipment the results of ordinary wear and tear neglect misuse accident and excessive deterioration due to corro sion from any cause are not considered to be a defect but Seller s liability for defective parts shall in no event exceed the furnishing of replacement parts f o b the factory where originally manufac tured Material and equipment covered hereby which is not man ufactured by the Seller shall be covered only by the warranty of its manufacturer Seller shall not be liable to Buyer for loss dam
16. wire to ground as seen below Analo Supply out J Ground Switched H 3 15VDC Analog In Datalogger Note The acceptable range of excitation voltages is from 3 15VDC If you wish to read the 10HS with Campbell Scientific data loggers you will need to power the sensors off of the switched 12V port rather than the excitation port If your 10HS is equipped with the standard 3 5mm plug and you wish to connect it to a non Decagon datalogger you have two op tions First you can clip off the plug on the sensor cable strip and tin the wires and wire it directly into the datalogger This has the ad vantage of creating a direct connection with no chance of the sensor becoming un plugged however it then cannot be easily used in the future with a Decagon readout unit or datalogger The other option is to obtain an adapter cable from Decagon The 3 wire sensor adapter cable has a connector for the sensor jack on one end and three wires on the other end for connection to a datalogger this type of wire is often referred to as a pigtail adapter Both the stripped and tinned adapter cable wires have the same termination as seen above the white wire is excitation red is output and the bare wire is ground 10 10HS Soil Moisture Sensor 6 Calibration 6 Calibration Dielectric calibration The 10HS comes pre calibrated to measure the dielectric per mittivity of the soil with the accuracy stated in the specification secti
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