What do I measure?  

Direct measurement of the soil water potential (suction). No calculation is necessary


Precise management of irrigations.
Management of adjusted water stress levels for seed production.
Water potential measurements at great depths.
Water stress management for modeling.
Checking water potential levels before starting a soil solution sampling campaign.
Following water percolation periods.
Water potential measurements at great depths (consult us).
Water potential measurements in unsaturated soils.
Soil water characteristic curves.
Studies on water flows percolation…
Studies on water resources: refilling of the water

The STCP 850 is an electronic tensiometer fitted with a pressure sensor pratically inside the porous ceramic cup. The miniaturization of the electronic sensor part allows a good integration, and thus a high reliability of operation.

This type of thensiometer has all electronic tensiometer advantages and more, so :

  • No temperature sensitivity (since the pressure sensor is in the soil, température fluctuations are very low)
  • Because the quantity of water inside the tensiometer is very low, the speed of tensiometer response is multiplied by 4.
  • The water columninside the tensiometer becomes here very short (about 10 mbar) and allows to use very deep installations.
  • The saturation procedure of tensiometer and its purge become very easy thanks to 2 capillaries.
  • Because, this tensiometer use a differential pressure sensor, it is no sensitive to atmospheric pressure variation.

The STCP 850 is proposed in different lengths and can be equiped with two types of ceramic pipe (standard or hight conductivity). The porous ceramic pipes used on this tensiometer are removable. So, these ceramic cup can be disassembled for clean up or replacement if broken.

Key Advantages

MONITORING (by connection to a data logger)

Frequent refill (the ceramic contains a small volume of water).
Available in mV output only.


Measuring range : 0 Hpa to -999 Hpa.
Ceramic : screwable ceramic, ref. SDEC 2150E.
Water refilling : by two nylon capillaries.
Accuracy : better than 1% of full scale.
Pressure sensor : differental pressure type with integrated temperature compensation.
Offset : factory calibrated. Each sensor is delivered with an individual calibration certificate.
Measuring process : sensor’s measurement at the bottom of the tensiometric tube = direct measurement of matric potential.
Output : On cable across nickel stuffing box.
Power supply : direct current; +6 to +15 Volts.
Temperature compensation : -10°C to +50°C.
Weight : 185 gramms.
Operating temperature : -10°C à + 50°C.
Storage temperature : -20°C à + 60°C.

The standard set

Each STCP type tensiometer tube is delivered ready to use with a integral pressure sensor and SDEC 2150E ceramic

You also need

. An auger to install the device, type STM 21600. A vaccum syringe, type TENS 22750 to prepare the tensiometer tubes and refill the capillaries.

Do the tensiometer tubes need to be prepared ? 

As all tensiometers, these tubes have a porous ceramic cup glued on the bottom. Before placing them into the soil, the ceramic must be saturated with gasless water. This can be done with a vacuum syringe, type STM 21750.

How often must the tubes be refilled ? 

Under normally rainy climate conditions or in irrigated cultural systems, the amount of water which leaks throught the porous ceramic into the soil is quite low. However, for maximum security, the tubes should be refilled after each measurement.

How is the sensor powered ? 

By the battery supply of the datalogger.

Main Menu