Sensors
Accurate soil water measurement starts in the ground. Choose the sensor that fits your soil, crop, and operation.
We offer two proven sensor technologies — the IRROMETER Tensiometer, a direct physical measurement of soil water tension, and the WATERMARK granular matrix sensor, a durable electronic alternative suited to a wide range of soil types and reading equipment.
Both technologies measure centibars of soil water tension and are compatible with our full range of reading tools. Many growers use both, matching sensor type to soil texture and rooting depth across different parts of their operation.
IRROMETER Tensiometers
The original commercial tensiometer — and still the standard by which other methods are tested. The IRROMETER measures actual soil water tension, unaffected by salinity and requiring no site calibration.
Available Models
Output Options
IRROMETER tensiometers can be connected to data collection and control equipment via switching gauges or electronic transducers — allowing integration with virtually any irrigation controller or data logger.
- Switching gauges for simple on/off irrigation control
- 4–20 mA output transducer for analog data loggers
- 0.5V–4.5V output transducer for direct sensor input
Length is selected based on the rooting depth of the specific crop. Multiple depths are typically installed together for a complete soil profile picture.
WATERMARK 200SS Sensors
A permanent, no-maintenance sensor buried in the root zone. The WATERMARK measures soil water tension electronically — no servicing, no refilling, works in freezing temperatures.
Key Features
- 0–200 centibar measurement range
- Stainless steel enclosure — will not dissolve in soil
- Not affected by freezing temperatures
- Internal compensation for typical salinity levels
- No maintenance, no refilling, no calibration
- Compatible with IC-10, 900M, handheld meter, and third-party devices
Works With Your Existing Equipment
WATERMARK sensors are widely used by industry partners in their own applications. For devices that read SDI or analog inputs, we offer adapter modules for direct integration.
SDI-12 output. Reads 3 WATERMARK sensors and 1 soil temperature sensor.
Spec Sheet0–3V analog output. Reads 3 WATERMARK sensors and 1 soil temperature sensor.
Spec Sheet0–3V analog output. Reads 1 WATERMARK sensor and 1 soil temperature sensor.
Spec SheetBuilding Your Own Device?
Our integration guide covers best practices for directly reading WATERMARK sensors, including an example Arduino implementation.