MPS-1 Dielectric water potential sensor
- Measurements:
- Applications:
The MPS-1 is an analog capacitance-based water potential sensor. It has been discontinued and replaced with the MPS-2 sensor.
Specifications
Part number 40851 (Stereo), 40853 (Pigtail), 40852 (Custom)
| Accuracy | ±40% of reading if no user calibration performed |
|---|---|
| Resolution | 1kPa from 0 to -100kPa, 4 kPa from -100 to -500kPa |
| Range | -10 to -500kPa (pF 2 to pF 3.71) |
| Measurement Speed | 10mS |
| Equilibration time | 10 min. to 1 hr. depending on soil water potential |
| Sensor Type | Frequency domain with calibrated ceramic discs |
| Output | 500 to 1000 mV DC correlated with water potential with a logarithmic relationship |
| Operating Environment | -40°C to 50°C |
| Power | 2 to 5VDC at ~25mA |
| Cable Length | 5m, custom cable lengths available |
| Cable Connector Types | 3.5mm "stereo" plug or stripped and tinned lead wires (3) |
| Sensor Dimensions | 75mm x 32mm x 15mm |
| Data Logger Compatibility (not exclusive) |
Decagon: Em50, Em50R, ProCheck Campbell Scientific: CR10X, 21X, 23X, CR1000, CR3000, etc. Other: Any data acquisition system capable of switched 2 to 5 V excitation and single ended voltage measurement at 12 bit or better resolution |
| Warranty | One year, parts and labor |
Comparisons
| Sensor | EC-5 (Analog) | 10HS (Analog) | 5TM (Digital) | 5TE (Digital) | MPS-1 (Analog) |
|---|---|---|---|---|---|
| Measures | Volumetric water content | Volumetric water content, dielectric permittivity | Volumetric water content, temperature | Volumetric water content, dielectric permittivity, temperature, electrical conductivity | Water potenial |
| Volume of Influence | 0.3L | 1L | 0.3L | 0.3L | N/A |
| Data Logger Compatibility | Em5b, Em50, Em50R, ProCheck, ECH2O Check, Campbell* | Em5b, Em50, Em50R, ProCheck, ECH2O Check, Campbell* | Em50, Em50R, ProCheck | Em50, Em50R, ProCheck, Campbell Scientific* | Em5b, Em50, Em50R, ProCheck, Campbell Scientific* |
| Range | 0-100%VWC | 0-53%VWC |
0-100%VWC, 40-50°C |
0-100%VWC, 40-50°C, 0-23dS/m | -10 to -500kPa (pF2 to pF 3.71) |
| Best if... |
VWC is all you need You're establishing a large sensor network |
You want large volume of influence |
You have high temperature variability in your soils You are monitoring shallow or desert soils where data must be corrected for temperature effects |
You are managing salts in your system You want to use SDI-12 |
You want to compare soil moisture at different research sites You want to determine water available for plant growth You are monitoring deficit irrigation |
| But not if... | You cannot apply regulated voltage (applies to non-Decagon data loggers) |
You are measuring in nursery pots. You are installing in rocky soil |
N/A | You want to monitor soilless substrates or potting soils. | You want to monitor soils at or near field capacity |
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 | 3-16 V |
| 5-TE | CR10X, CR1000, CR3000, etc. | Ask a Decagon representative for an integrator’s guide to interfacing the 5-TE | Digital ASCIII stream or SDI-12 | 3-16 V (3.6 best) |
| 5-TM | CR10X, CR1000, CR3000, etc | Ask a Decagon representative for an integrators guide to interfacing the 5-TM | Digital ASCII Stream or SDI-12 | 3-16 V (3.6 best) |
| MPS-1 | CR10X, 21X, 23X, CR1000, CR3000, etc. | Any data acquisition system capable of switched 2 to 5 V excitation and single ended voltage measurement at 12 bit or better resolution. | voltage correlated with water potential, independent of excitation | 2.5-12 V |
Accessories
Auger Kit
For use with deep installation of the ECH2O probes. Includes a regular and sand auger (2.75" [7 cm] diameter), two 2' (0.6 m) extension rods, a standard rubber handle, and a ratchet handle.
Splice Kit
Repair damaged cables in the field with few tools and less time.
Support
Software & Downloads
Application Notes
Manuals
How-To Articles
- Using SCWin (Short Cut) to read EC-5, -10, and -20, MPS-1, and 10HS Sensors with Campbell Scientific
Video
Request Support
Email: support@decagon.com
Phone: 800-755-2751 or
509-332-2756
Fax: 509-332-5158
Or send us an information request:
Education
Newsletters
Virtual Seminar
- September 28, 2010: Virtual Seminar: Quick Methods for Determining Plant Available Water
- July 27, 2010: Virtual Seminar: New Vadose Zone Monitoring Technology