Irrometer Watermark Meter

Irrometer Watermark Meter


The WATERMARK Meter is a hand held device designed for reading WATERMARK sensors in the field. The digital readout displays the sensors’ soil moisture status in centibars (cb) or kilopascals (kPa) of soil water tension. This value represents the energy a plant’s root system uses to draw water from the soil. Whereas higher tension values indicate dryer soil, lower tension values indicate wetter soil. The meter’s replaceable cable assembly has spring loaded clips for attaching to sensor leads. Users only need one meter to read any number of WATERMARK sensors. The meter comes in its own nylon case, padded and zippered for safe keeping when not in use.


  • Large LCD display is easy to see in sunlight
  • Touch pad operating panel is simple to use and has a self test function
  • Quick release cable assembly is field changeable
  • Adjustable for soil temperature variations

WATERMARK Digital Meter

  • COMPATIBILITY: The WATERMARK meter is designed to read WATERMARK sensors exclusively
  • POWER REQUIREMENTS: Self powered 9 VDC internal battery MATERIALS: ABS plastic case with touchpad controls (tactile switches) DIMENSIONS:
  • HEIGHT: 4.750 in. (121 mm) [ 5.25 in. (140 mm) including cable recepticle]
  • WIDTH: 2.75 in. (70 mm)
  • DEPTH: 1.0 in. (25 mm)
  • CABLE: 50 OHM coaxial cable [ 24 in. (.6 m)] with bayonet type connection (BNC) on the meter end and two alligator clips on the sensor end
  • DISPLAY: 0–199 cb (kPa) of soil water tension WARRANTY: One year
  • OPERATING PRINCIPLE: The WATERMARK meter is designed to read all WATERMARK soil moisture sensors exclusvely. These sensors have an output of 500–30,000 ohms of electrical resistance which is non-linear. The meter uses a solid-state alternating current resistance bridge meter for reading the sensors and converts the resistance value into centibars (cb) or kilopascals (kPa) of soil water tenson. The reading is displayed on an LCD screen [ range 0 –199 cb (kPa)]

Soil temperature values can be input by the user to compensate for their effect on sensor reading.

SPECIFICATION INFORMATION: The soil moisture monitoring system shall incorporate Granular Matrix Sensors (GMS) to measure soil water tension. The sensors shall use a digital meter to read sensor values. The meter shall have a soil temperature compensation feature and self test functions on its tactile keypad. The meter shall be the model #30- KTCD-NL WATERMARK digital meter as manufactured by the IRROMETER Company, Inc. of Riverside, California.


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