4-20 Milliamp output, ultra-long cable lengths
The MAS-1 4-20 milliamp 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.
Research grade accuracy
The MAS-1 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.
Low cost individual sensors for large sensor networks
The MAS-1 delivers research-grade 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.
Advantages of the MAS-1
- 4-20 milliamp sensor
- Allows for cable lengths greater than 250 feet
Specifications
| INTERFACE | Standard 4-20 mA analog transmitter |
| SUPPLY VOLTAGE | 12-32 VDC continuous |
| OUTPUT CURRENT | 4 – 20 mA |
| OVERVOLTAGE PROTECTION | Yes |
| 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 aquistion) 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*
*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. |
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