Equitensiometer - EQ2

• Maintenance-free dielectric tensiometer
• Wide range -50 to -500 kPa
• Simple data logger connection
• No frost damage

The Equitensiometer is an innovative sensor for measuring soil water potential (soil matric potential).

Advantages

Based on the ML2x ThetaProbe, the EQ2 avoids the familiar problems of water-filled tensiometers. The ThetaProbe pins are embedded into a specially formulated porous matric material. Being maintenance free, (i.e. no refilling, degassing or topping up required) and low power, the EQ2 can be conveniently used at remote sites. It is not harmed by frost, nor by long term burial.

Applications

The EQ2's full range is 0 to -1000 kPa but best accuracy is achieved between -100 and -500 kPa. This makes it well suited to plant water stress studies - even in very dry soils. However, the EQ2 should not be seen as a rapid response, high accuracy device covering the full range of water potentials, as such a sensor does not yet exist. EQ2 equilibration time is typically several days. Extension Tubes can be used to position EQ2s at depth.

Data Logging

The Equitensiometer is compatible with the Delta-T DL2e Logger and with other loggers able to handle powered sensors with a millvolt output. In applications where it is acceptable to measure only the unconverted millivolt output from the EQ2, a DL6 Logger can be used for continuous recording, or an HH2 moisture meter used for spot readings.

The EQ2 requires a DC power supply of 5 to 15V at 20mA (typical) and produces a DC output (150 to 550mV for 0 to -1000 kPa, non-linear).