MP306 Moisture Sensor

Measure volumetric soil moisture for scientific research, agriculture and civil engineering

The MP306 has a compact body and the needles are arranged in a single plane making it ideal for use in soil columns. It is also ideally suited to measuring pots in glasshouses and growth cabinets. The MP306 can also be installed in the field, with a lifespan of 20+ years in the most extreme conditions.

The MP306 can be used to take continuous measurements over time through permanent or temporary burial and connection to a SMM Soil Moisture Meter. The sensor has a compact body and the needles are arranged in a single plane making it ideal for use in soil columns, enabling measurement of discrete soil layers within the column. Similarly in soil profiles, narrow layers can be precisely measured.

The MP306 is also used to measure the moisture content in materials used in mining, roadway and buildings. The material that can be measured is often soil but can be any composition of non-metallic powdered, liquid or solid substance into which the needles are inserted. It is especially suitable for mineral stock piles, mine tailings and sand for batch mixing of concrete.

The MP306 Soil Moisture Sensor can also measure soil water potential via the SMM Soil Moisture Meter and a soil water characteristic curve.

MP306 Soil Moisture Sensor Features

  • Volumetric Soil Water Content (%) or can simultaneously measure soil water potential
  • Highly accurate and precise
  • Robust, stainless steel needles and epoxy body
  • Measures in saline, toxic and high temperature soils
  • Rapid measurement
  • Can be buried for up to 20 years

MP306 Soil Moisture Probe


Measurement Range 0-100 VSW%
Accuracy 1% VSW% after calibration to a specific soil type
± 5 VSW% using the supplied soil calibration
Resolution 0.01% VSW%
Response Time Less than 0.5 seconds
Stabilisation Time 3 seconds approximately from power-up


Input Requirements 9-18 V DC unregulated
Power Consumption 14 mA typical, 16mA max
Output signal 0-1160mV for 0-100 VSW%


Total Length 199 mm
Needle Length 60 mm
Needle Seperation 8 mm
Needles Stainless Steel (Grade 316) – does not corrode in saline solutions
Exterior ABS Plastic
Cable 4.5m Standard


Environment Designed for permanent or temporary burial