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 a total of 2x GT3-15 Transducers to monitor soil tension at multiple depths.
The GT3-15 Transducer couples with a preferred Jet Fill Tensiometer (see available lengths here). The Jet Fill Tensiometer measures the force with which water is held in the soil by the soil particles.
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
The Multifunction Research Node has been designed to provide flexible communication, sensor and power options.
The MFR-NODE supports SDI-12 and 4 x dry contact digital inputs as well as optionally 2x differential / 4x single ended analogue inputs. The MFR-NODE supports sensors with higher power requirements; a solar panel can charge either the internal lithium-ion battery or both the node and sensor can be powered by an external 12V system (e.g. battery or mains source). Optional CAT-M1 provide an option for remote installation and in areas outside the range existing LoRaWAN networks. The optional multiconstellation GNSS ensures you won’t lose track of your device. The MFR-NODE has an onboard 8GB SD Card to provide data logging capabilities and full data redundancy in the event of temporary loss of communications or dropped packets – ideal for research applications.
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.
|Range:||+100kPa to -100kPa|
|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|