laboratory TDR probe

Lab TDR ProbeAn ideal solution for research scientists and engineers for laboratory, soil columns and glasshouse applications, the LP/ms is a small time domain reflectometry (TDR) probe for the accurate measurement of soil volumetric water content, salinity and temperature.

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Soil Moisture ProbeLP/ms is a small laboratory TDR probe for the measurement of moisture and salinity (by means of bulk electrical conductivity) of porous bodies, especially soil. Its size and shape is designed to fit into cylindrical containers and enable testing small samples. It can be used for monitoring the changes in water and salt distribution in soil columns or in soil cores sampled with standard sampling equipment.

Several LP/ms probes can be inserted through the side wall of a soil column or a steel sampling cylinder, thus allowing for vertical scanning of the instantaneous moisture and electrical conductivity profiles. Such an array, when combined with similarly installed minitensiometers LP/p, enables collecting a set of corresponding water content and matric potential gradient data from drying or wetting front transition. This allows for determination of a complete set of the soil unsaturated water flow characteristics, i.e.: water retention (PF-curve), water conductivity (k-function), differential water capacity and unsaturated water diffusivity.

  • soil moisture and salinity sensorMeasurement of moisture and electrical conductivity.
  • Small measurement volume for precision and specialised experiments.
  • Applicable for laboratory use.
  • Dedicated calibrator block from polyacetal (ε = 3.8) for precise calibration.
feature specification
Measurement Principle Time Domain Reflectometry (TDR)
Sensor Dimensions 2 parallel stainless steel rods | 53 mm Length | 0.8 mm Diameter spaced 5 mm apart (larger probes available upon request)
Cable Length 1.5m (standard) | Up to 6m (optional)
Measurement Range
Soil Volumetric Water Content 0 to 100 %
Temperature -20 to 50 °C
Electrical Conductivity/Salinity 0 to 1 S/m
Measurement Accuracy
Soil Volumetric Water Content ± 2% or less with soil specific calibration
Temperature ± 0.5 °C
Electrical Conductivity/Salinity ± 10%
Measurement Resolution
Soil Volumetric Water Content 0.1 %
Temperature 0.1 °C
Electrical Conductivity/Salinity 1 mS m-1
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