The vacuum inside the tensiometer is measured by a pressure transducer, which gives a continuous analogue output signal. A resolution of 0.1 kPa (1 cm H2O) can be attained for the GT3 Tensiometer Transducer.
GT3-1 Tensiometer Transducer -7 to 7 kPa Features
|Range:||+7kPa to -7kPa|
|Signal:||At input 10.0 V output signal is: 0 kPa = 0 +/- 3 mV and -100 kPa = -100 +/- 3 mV|
|Temperature shift:||Temperature compensated in the range 0–50°C—typical shift 0.5% full scale.|
|Voltage output:||Transducer has a 4 wire output signal.|
|Power Supply:||10.0 V DC typical, 16.0 V maximum stabilised|
|Current consumption:||1.3 mA @ 10.0 V|
The soil water tension is transmitted via the ceramic cup into the tensiometer. The vacuum inside the tensiometer is measured by a pressure transducer, which gives a continuous analogue output signal.
A resolution of 0.1 kPa (1 cm H2O) can be attained for the GT3 Tensiometer Transducer.
The accuracy actually obtained is related to the calibration and resolution of the AD converter. In field applications the values obtained should consider the shaft/cup length of the tensiometer: 1 cm = 0.1 kPa.
Red: +10 V power supply
Yellow: Signal output “+”
Pressure change from 0 to -100 kPa
Output from 0 to -100 mV
Black: Battery ground
Blue: Signal output “-”
Do not connect signal output “-” to battery ground