This sensor switches your garden irrigation pump or the magnetic valve on when the soil is dry and switches off when there is enough humidity in the soil. The measuring head has to be buried into the ground at the depth where it shall measure and has to be connected with the basic device via a cable. Approx. 2 m of cable are included, the sensor cable may, however, be prolonged up to 20 m with normal 2-pole cable. The device is operated by means of a commercial plug power supply (12 V/DC stabilized, > 130 mA, jack plug 3.5 mm). If the garden shall be irrigated at certain times of the day or weekdays only, then please put a commercial timer before the plug power supply and program it accordingly. The soil humidity sensor starts to operate when it receives current from the power supply.
The soil humidity is measured after switching on the operating voltage. The connected pump is switched on for 18…30 minutes if the soil is too dry. If the soil is humid enough the device switches to „Pause“ for about 18 – 30 minutes and makes a new measurement after that. This continues as infinite loop until the operating voltage is switched off.
Operating voltage 12 V/DC stabilized > 130 mA, jack bush 3.5 mm
Display 3 LEDs: “On” … “Off”…”Pause”
Switching contact potential-free relay contact 1 x On max. 3 A (up to 25 V or also 230 V/AC, see description)
Connections screw terminals
Time delays ca. 18 – 30 minutes in each case
Switching threshold continuously adjustable
The basic device must be mounted in a dry place.
Dimensions soil humidity sensor diameter ca. 30 x 64 mm plus 2 galvanized metal pins ca. 4 x 40 mm
Dimensions basic device ca. 72 x 50 x 28 mm (without fastening straps)