This sensor can measure the amount of moisture present in the surrounding soil by using two electrodes that pass current through the ground, and read the resistance. Greater presence of water makes the earth conducts electricity easier (Less resistance), while a dry soil is a poor conductor of electricity (greater resistance).
For application as humidity sensor in soil for long periods of time, it is recommended to power the electronic module automatically to turn it on only when taking measurements, turning it off immediately upon completion and thus minimize electrolytic corrosion. It is also possible to exchange the connections of the sensor element periodically so that the two electrodes rotate polarity.
Analog measure of humidity with voltage variation output (AO)
Digital threshold exceeding signal with user output (DO) and LED indicator. The trigger sensitivity can be adjusted by trimmer. This function is provided by a comparator with LM393
Card connection pins: VCC: power supply, GND: Earth, DO: Digital output indicating threshold exceeding, AO: Analog output of the humidity measurement
Power indicator LED
Supply voltage: 2 V to 6 V
Two fixing holes in the sensor diameter 3 mm approx. and a clamping hole in the electronic module of 2 mm approx.
I includes 6 Female-Female connection cables of 20 cm.
Dimensions approx: Sensor 6 cm x 2 cm. Electronic module 4 cm x 1.5 cm
Monitoring of humidity in soils
Detection of maximum level in a tank