null, pub-0015564483429508, DIRECT, f08c47fec0942fa0

Irrometer 200SS-X, 6in Watermark Soil Moisture Sensor

Price $66.98
Minimum Purchase:
1 unit

FREE SHIPPING (Continental US) | Estimated ship in 4-7 business days
* Estimate is for US customers only.
* Shipping and Import Duties are calculated at checkout.
See Product Information

200SS-X 6" (15cm) Cable Length | Watermark Soil Moisture Sensor by Irrometer

  • Standard WATERMARK Soil Moisture Sensor for use with all crops in most soils.
  • To be used with WATERMARK Meter, Monitor, Voltage Adapter or a compatible device.
  • Reads electrical resistance in 0-200 centibar (cb) and kilopascal (kPa) range.
  • Comes standard with half inch stripped and tinned ends (also available with pipe spigot ends).
  • Available in 5', 15' and 6" cable lengths.
  • Galvanic isolation may be required for some reading devices. See 200SS-V-6.

In use since 1978, the patented WATERMARK sensor is a solid state electrical resistance sensing device that is used to measure soil water tension. As the tension changes with water content the resistance changes as well. That resistance can be measured using the WATERMARK Sensor.

The sensor consists of a pair of highly corrosion resistant electrodes that are embedded within a granular matrix. A current is applied to the WATERMARK to obtain a resistance value. The WATERMARK Meter or WATERMARK Monitor correlates the resistance to Centibars (kilopascals) of soil water tension.

The WATERMARK is designed to be a permanent sensor, placed in the soil to be monitored and “read” as often as necessary with a portable or stationary device. Internally installed gypsum provides some buffering for the effect of salinity levels normally found in irrigated agricultural crops and landscapes.


  • 0-200 Centibar range
  • Stainless steel enclosure
  • Fully solid state
  • Will not dissolve in soil
  • Not affected by freezing temperatures
  • Internal compensation for commonly found salinity levels
  • Inexpensive
  • Easy to use
  • No maintenance necessary
  • Can be installed on pipe (see illustration diagram)

Data Options

WATERMARK sensors can be read by a variety of our devices, including a handheld meter, 8 channel data logger, and wireless mesh networks.

 Irrometer 200SS-X, 6in Watermark Soil Moisture Sensor

Irrometer 200SS-X, 6in Watermark Soil Moisture Sensor