Passive water sensors

The water sensors for connection to the water detectors for fixed installation are passive sensors, i.e. in principle they are refined, low-corrosion cable ends.
A passive sensor does not emit a signal and does not change its properties on contact with water.
Rather, it is the water detector itself that emits a signal in the form of a 120 Hertz square wave with 2.5 Vpp to one of the sensor contacts and "sees" on the other line what comes back from it. If the sensor is in the dry, none of the square wave is transmitted to the other line. If, on the other hand, both contacts are in the same puddle of water, the conductivity of the water will send the square wave back to the water detector. In the case of the water detectors from Elektrotechnik Schabus, the resistance must be below approx. 80 kOhm so that an alarm is triggered.
However, this also requires conductive water, i.e. water that is not pure, in which free ions move and which can therefore conduct electricity.

Quite "normal" water, as it comes out of our water pipe, which perhaps enters our house as rain or also enters our boat as fresh water, always has sufficient conductivity.
Demineralized or also distilled water, which usually also includes condensation water, is usually not conductive enough to be detected by a water detector via sensor.

Water sensors are suitable only for regularly dry environments and must not detect the water level in shafts, tanks, the pump sump or other containers. Mini float switches are always taken for a water level, or stroke. Water sensors are only suitable for floors, surfaces, etc. to quickly detect moisture, e.g. under a washing machine.
Sensors that are under water for a while draw the water inside and frequent false alarms are the result. In this respect, each water sensor is a wearing part and a defect is not covered by any warranty.