Direct physical reading of soil water tension
No maintenance, high value, granular matrix sensor
The IRROMETER Tensiometer is the standard in accurate soil moisture measurement, offering growers an inexpensive and reliable means of measuring soil moisture for irrigation scheduling. An IRROMETER will measure the actual soil water tension, which indicates the effort required by root systems to extract water from the soil. Because the IRROMETER is a true measurement of soil water potential, the instrument is not affected by salinity and does not require site calibration.
The IRROMETER is available in several models, with standard lengths of 6", 12", 18", 24", 36", or 48" dependent on the rooting depth of the specific crop.
The "SR" IRROMETER is the standard instrument for use in medium to heavy soils. Each instrument includes a threaded replaceable tip as well as reservoir, air free gauge chamber, and membrane vented stainless steel vacuum gauge with a 0 to 100 cb/kPa soil water tension range.
SR IRROMETER Spec SheetThe "LT" IRROMETER is fitted with a low tension 0-40 cb/kPa gauge for applications where tensions above 30 are rarely expected. Ideal for very coarse soils, sands, and non-soil containter media where soil water tension changes rapidly in the lower end of the scale.
LT IRROMETER Spec SheetThe "MLT" (Miniature Low Tension) is designed for applications similar to the Model "LT" above where small size is required. Ideal for use with very coarse soils and non-soil container-media. Its compact size and 0-40 cb/kPa gauge make it a good choice for green house applications.
MLT Spec SheetOUTPUT OPTIONS: Additional options for connecting IRROMETER tensiometers to data collection or control devices are available, including switching gauges as well as 4-20mA and 0.5V to 4.5V output transducers.
Output Options
Additional Resources:
In use since 1978, the patented WATERMARK sensor (PN: 200SS) is an electrical sensing device that is buried in the active root zone to measure soil water tension.
The sensor consists of corrosion resistant electrodes embedded within a specialized granular matrix. Water in the soil exchanges with the sensor matrix, providing a measurement of centibars (or kPa) of soil water tension equivalent to the readings from an SR or LT tensiometer.
The WATERMARK is designed to be a permanent sensor, left in the soil to be read by logging devices or handheld readers. We offer our own reading solutions, but the sensor is also widely used by industry partners in their own applications.
WATERMARK sensors require a reading device designed specifically to read them. For other devices which can read standard analog sensors, we offer adapters to allow easy integration:
200SS-SDI Adapter - SDI module that reads three WATERMARK and 1 200TS Soil Temp Sensor
200SS-VA Adapter - Adapter reads one WATERMARK and outputs standard 0-3V analog signal
For directly integrating WATERMARK sensors in to your device project, our integration guide covers best practices and includes an example Arduino implementation:
WATERMARK Integration Guide