Tensior T8 - Eijkelkamp Agrisearch Equipment

4 Description of the T8
4.1 Output signals
The T8 is optimised for in-the-field use. Signals for soil water tension, soil
temperature and filling status are offered.
Water tension and temperature are linear voltage signals 0 ... 2 V. Thus, the
signals are directly connectable to nearly any datalogger or other data
recording device.
The IR indicator works like a switch so the filling status can have two levels:
"0V" (switch is open) for correct filling, or Vin = power supply voltage (switch
is closed) if the Tensiometer needs to be refilled.
4.2 Sensor body
The complete electronic of the T8 is integrated in the sensor body. The
housing consists of glass-fibre reinforced synthetic. All electronic parts are
completely covered with epoxy resin - the optimal and everlasting protection
against moisture.
The T8 is calibrated electronically by
programmable potentiometers. The calibration is
stored in EPROM's.
4.2.1 Pressure sensor
The piezoelectric pressure sensor measures the soil water tension against the
atmospheric pressure. The atmospheric pressure is conducted through a
watertight diaphragm (the white, 2 cm long tube on the cable) and through the
cable to the reference side of the pressure sensor.
The non destructive maximum pressure is 3.000 hPa. Higher pressure will
damage the sensor and absolutely must be avoided!
10
Sensors and refilling tube on sensor body