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.
Utilising the GT3-15 Tensiometer Transducer sensor in a custom IoT (Internet of Things) package
The SNiP-GT3 is a ‘Sensor Node Integrated Package’ for LoRaWAN or CAT-M1 communication of real-time soil tension measurements for continuous soil monitoring.
The base SNiP-GT3 integrates an MFR-NODE and 1x GT3-15 Transducer to a site’s unique network, communication and power requirements. The MFR-NODE can support an added 1x GT3-15 Transducer to monitor soil moisture at multiple depths.
The GT3-15 Transducer couples with a preferred Jet Fill Tensiometer (see available lengths here).
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 100 to -100 kPa
Output from 0 to -100 mV
Black: Battery ground
Blue: Signal output “-”
Do not connect signal output “-” to battery ground
|Range:||+100kPa to -100kPa|
|Signal:||Ratio Metric to its supply voltage. Differential Output. At input 10.0 V output signal is: -100 kPa = -100 +/- 3 mV and 0 kPa = 0 +/- 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|