GS3 Soil Moisture Sensor
- Measurements:
- Applications:
Same Internal Circuitry, Optimized New Form Factor
The GS3 soil moisture, temperature, and EC sensor is the newest sensor in the Decagon system. The internal circuitry is the same cutting edge design that you'll find in other Decagon soil moisture sensors, but the form factor has been optimized for use in soilless substrates. The steel needles not only slice through the substrates for perfect contact, but they also improve the sensor's ability to measure EC in porous substrates such as peat or perlite. The sensor also works well in mineral soils.
Accuracy at a Fraction of the Cost
The GS3 measures water content, temperature, and EC independently. Its 70 MHz frequency minimizes salinity and textural effects, making it accurate in most soil or soilless media. Stainless steel needles have an extended surface area to optimize EC measurements, while minimizing substrate disturbance during insertion. Temperature is measured with an onboard thermistor; and electrical conductivity is measured using a stainless steel electrode array.
Understand Your Measurements
When used in conjunction with our DataTrac 3 software, your GS3 data can be used to determine plant available water, growing degree days, and pore water electrical conductivity.
Integrate with Campbell Scientific Data Loggers
Each GS3 comes standard with both serial and SDI-12 communication options, meaning easy integration with systems manufactured by other companies (such as Campbell Scientific).
Reasons to Pick the GS3:
- If you need to measure VWC, EC, and temperature in soilless substrates.
- If you are managing salts in your system.
- If you want to use SDI-12.
Specifications
Part number 40557 (Stereo), 40558 (Pigtail), 40559 (Custom)
| Accuracy |
Apparent Dielectric Permittivity (εa): ± 1 εa (unitless) from 1 - 40 (soil range), ± 15% from 40 - 80 Soil Volumetric Water Content (VWC):
Electrical Conductivity (EC): ± 10% from 0 to 10 dS/m, user calibration required above 10 dS/m Temperature: ± 1°C |
|---|---|
| Resolution |
εa: 0.1 εa (unitless) from 1 - 20, < 0.75 εa (unitless) from 20 - 80 VWC: 0.002 m3/m3 (0.2% VWC) from 0 to 40% VWC, 0.001 m3/m3 (0.1% VWC) > 40% VWC EC: 0.001 dS/m from 0 to 23 dS/m Temperature: 0.1°C |
| Range |
εa: 1 (air) to 80 (water) EC: 0 - 23 dS/m (bulk) Temperature: -40 - 50°C |
| Measurement Speed |
150 ms (milliseconds) |
| Sensor Type |
VWC: Frequency domain EC: Two probe design Temperature: Thermistor |
| Output | Serial TTL, 3.6 Volt Levels or SDI-12 |
| Operating Environment | -40°C to 50°C |
| Power | 3.6 - 15 VDC, 0.3 mA quiescent, 25 mA during 150 ms measurement |
| Cable Length | 5 m standard, custom cable lengths available upon request |
| Cable Connector Types | 3.5 mm "stereo" plug, or stripped and tinned lead wires (3) |
| Sensor Dimensions | 9.3 cm x 2.4 cm x 6.5 cm |
| Data Logger Compatibility (not exclusive) |
Decagon: Em50, Em50R, Em50G, ProCheck Campbell Scientific: Any logger with serial I/O (CR10X, CR850, CR1000, CR3000, etc.) Other: Any data acquisition system capable of 3.6-15V excitation and serial or SDI-12 communication |
| Warranty | One year, parts and labor |
Comparisons
| ANALOG SENSORS | DIGITAL SENSORS | |||||
| SENSOR | EC-5 | 10HS | 5TM | 5TE | GS3 | MPS-2 |
|---|---|---|---|---|---|---|
| MEASURES | volumetric water content, dielectric permittivity | volumetric water content, dielectric permittivity | volumetric water content, dielectric permittivity, temperature |
volumetric water content, dielectric permittivity, temperature, electrical conductivity | volumetric water content, dielectric permittivity, temperature, electrical conductivity | water potential temperature |
| VOLUME OF INFLUENCE | 0.3 L | 1 L | 0.3 L | 0.3 L | 0.3 L | N/A |
| DATA LOGGER COMPATIBILITY | Em5b, Em50, Em50R, Em50G, ProCheck, ECH2O Check, Campbell Scientific* | Em5b, Em50, Em50R, Em50G, ProCheck, ECH2O Check, Campbell Scientific* |
Em50, Em50R, Em50G, ProCheck, Campbell Scientific*, SDI-12 capable |
Em50, Em50R, Em50G, ProCheck, SDI-12 capable |
Em50, Em50R, Em50G, ProCheck, SDI-12 capable |
Em50, Em50R, Em50G, ProCheck, SDI-12 capable |
| RANGE | 0 - 100% VWC | 0 - 53% VWC |
0 - 100% VWC 40 - 50°C |
0 - 100% VWC 40 - 50°C 0 - 23 dS/m |
0 - 100% VWC 40 - 50°C 0 - 23 dS/m |
-5 to -500 kPa (pF 2 to pF 3.71) -40°C to 50°C |
| BEST IF | VWC is all that you need. You're establishing a large sensor network. |
You want a large volume of influence. |
You have high temperature variability in your soils. You need to monitor soil temperature for biological activities. You want to use SDI-12. |
You are managing salts in your system. You want to use SDI-12. |
You are measuring water content of soilless substrates. You need high accuracy EC. |
You want to compare soil moisture at different research sites. You want to measure water potential. |
| BUT NOT IF | You cannot apply a regulated voltage (only applies to non-Decagon data loggers). | You are measuring in nursery pots. You are installing in rocky soil. |
N/A | You want to monitor soiless substrates or potting soils. | You are doing downhole installations. | You want to monitor soils at or near saturation. |
Compatibility and Programming Specifications for Campbell Scientific and Other (non-Decagon) Data Loggers
Note: ECH2O sensors are “plug and read” on Decagon data loggers. You do not need to program any of this information (or ANY information) into a Decagon logger.
| SENSOR | CAMPBELL COMPATIBILITY | OTHER LOGGERS | OUTPUT | VOLTAGE REQUIREMENTS |
|---|---|---|---|---|
| EC-5 | CR10X, 21X, 23X, CR1000, CR3000, etc. | Any data acquisition system capable of switched 2.5 to 3.6 V excitation and single ended voltage measurement at 12 bit or better resolution. (Note: some people take their chances with resolution as low as 3 bits, but resolution lower than 10 bits will leave the data quite choppy). | Voltage, correlated linearly (soil) or polynomially (growing media) with VWC | 2.5-3.6V |
| 10HS | CR10X, 21X, 23X, CR1000, CR3000, etc. | Any data acquisition system capable of 3-15 VDC excitation and single ended voltage measurement at 12 bit or better resolution. | Voltage correlated with VWC, independent of excitation | 3-15 V |
| 5TE | Any logger with serial I/O (CR10X, CR850, CR1000, CR3000, etc.) | Ask a Decagon representative for an integrator’s guide to interfacing the 5TE | Digital ASCIII stream or SDI-12 | 3.6-15 V |
| 5TM | Any logger with serial I/O (CR10X, CR850, CR1000, CR3000, etc.) |
Ask a Decagon representative for an integrators guide to interfacing the 5TM | Digital ASCII Stream or SDI-12 | 3.6-15 V |
| GS3 | Any logger with serial I/O (CR10X, CR850, CR1000, CR3000, etc.) |
Ask a Decagon representative for an integrators guide to interfacing the GS3 | Digital ASCII Stream or SDI-12 | 3.6-15 V |
| MPS-2 | Any logger with serial I/O (CR10X, CR850, CR1000, CR3000, etc.) |
Ask a Decagon represenative for an integrators guide to interfacing the MPS-2 | Digital ASCII Stream or SDI-12 | 3.6-15 V |
Support
Application Notes
- Calibration and Evaluation of an Improved Low-Cost Soil Moisture Sensor
- Campbell Scientific Programs for the 5TE, 5TM, and the GS3
Software & Downloads
How-To Articles
Manuals
Video
Request Support
Email: support@decagon.com
Phone: 800-755-2751 or
509-332-2756
Fax: 509-332-5158
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