ML3 ThetaProbe Soil Moisture Sensor

Delta-T Devices offers the new ML3 ThetaProbe as a replacement to its previous ML2x ThetaProbe model, with new and improved performance, quality and reliability.

The new device not only reliably and accurately measures soil moisture, but can also (when buried) measure soil temperature thanks to the integration of a thermistor sensor.

By simply connecting to any Delta-T data logger, including the new GP2, the ML3 ThetaProbe makes soil moisture measurements within seconds.

The ML3 ThetaProbecan be connected to the HH2 Moisture Meter for portable applications. Moreover, Delta-T Devices offers the ML3 along with the convenient ThetaKit, which consists of spare ThetaProbe rods, an HH2 Soil Moisture Meter readout unit, insertion kit and carrying case.

This combination provides rapid spot readings of the moisture content and temperature of the soil.

Key Features

The following are the key features of the new ML3 ThetaProbe soil moisture sensor:

  • New built-in temperature measurement
  • Measures Soil moisture content with ± 1% accuracy
  • New white body minimizes radiative heating
  • Enhanced calibration for soil salinity
  • New extendable cable system enables flexible configurations
  • Improve temperature range allows operating temperatures as low as -40 °C
  • Robust, buriable and maintenance free
  • Environmentally protected to IP68.


With a predictable saline response, the ML3 can be utilized in saline soils of up to 2000 mS.m-1. It can also be utilized in non-soil media.

Typical application areas of the ML3 include:

  • Forestry
  • Pollution monitoring
  • Soil water profiling
  • Civil engineering
  • Hydrology
  • Irrigation.

Other Equipment by this Supplier