The MAS-1 4-20 milliamp soil moisture sensor is the first current-based sensor to use METER’s trademark 70 MHz technology. This sensor offers a standard 4-20 milliamp output that is common with PLCs and irrigation controllers. With the 4-20 mA interface, cable lengths over 250 feet are possible.
The MAS-1 soil moisture sensor determines volumetric water content (VWC ) by measuring the dielectric constant of the media using capacitance/frequency domain technology. The sensor uses a 70 MHz frequency, which minimizes salinity and textural effects, making the MAS-1 accurate in almost any soil or soil-less media. Factory calibrations are included for mineral soils, potting soils, and rockwool.
The MAS-1 delivers research-grade soil moisture accuracy at a price that makes large sensor networks economically practical. You can adequately characterize your site with sensors at multiple depths and locations, even if you’re on a tight budget.
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|Interface||Standard 4-20 mA analog transmitter NOTE: Temperature measurement may not be accurate if sensor is not fully immersed in the medium of interest, due to excessively long equilibration time.|
|Supply Voltage||12-32 VDC continuous|
|Output current||4 – 20 mA|
|Settling time||4 seconds|
|Wiring||Red Wire: (+) supply|
Black Wire: (-) output
Shield: not connected
|Sensor type||Volumetric Water Content (VWC)|
|Range||0-100% VWC typical|
|Resolution||Depends on current measurement (data acquisition) device|
|Accuracy||±6% VWC with generic calibration for supported growing media up to 65% VWC, above which accuracy lessens. Increased accuracy can be achieved with a medium-specific calibration.|
|Output||4-20 mA current proportional to VWC|
|Sensor measurement interval||1 second|
|Operating environment temperature|
-40 to 60 °C
NOTE: Sensors can be used at higher temperatures under some conditions. Contact METER for more details.
|Physical properties dimensions||8.9 cm x 1.8 cm x 0.7 cm|
|Cable||2 m or 5 m, 3 wire (22 AWG tinned red and black wire, 24 AWG tinned bare wire); custom cable length available upon request.|
|Measurement volume||See comparison article|
|MAS-1 Manual||Manual||PDF, 1.106MB||Download MAS-1 Manual Manual|
|**SOIL MOISTURE SENSOR CALIBRATION GUIDE||Instructions||PDF, 0.6MB||Download **SOIL MOISTURE SENSOR CALIBRATION GUIDE Instructions|
|Sensor Wire Splicing Guide (Quick Method)||Instructions||PDF, 0.9MB||Download Sensor Wire Splicing Guide (Quick Method) Instructions|
|Sensor Wire Splicing Guide (Complete Method)||Instructions||PDF, 5MB||Download Sensor Wire Splicing Guide (Complete Method) Instructions|
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