How Our Analog Water Sensor Works

Most water sensors measure the difference between the conductivity of air and the conductivity of water.  ITWatchDogs water sensors have a low voltage applied to four metal brads on a plastic case.  When the water touches the brads, it completes the circuit and the current begins to flow.  IF the metal brads are touching a surface such as a concrete floor, the graphs will show a decrease from reading 99 (dry, no current flow) to 80 (damp) to 55 (full conductivity).

The water sensors plug into the analog-sensor ports in ITW products

When installing the water sensor, be sure that the surface the sensor is placed upon is non-conductive.  Since the sensor detercts water by electrical conductivity between the metal brads, if those brads are in contact with a conductive surface - such as a metal tray - the sensor will always show full conductivity, wet or dry.

1. The sensor must face down - metal brads against the floor
2. Placement locations:
1. water collection trays such as the trays below sprinklers.
2. Lowest point on the floor or below raised flooring.  To find the lowest place on floor, spill some water and see where it puddles in your server room - that's a perfect place for a water sensor.
3. Below a water pipe junction
4. In back-up air-conditioning condensation trays.
5. Test the sensor.  Dunk it in a glass of water and see if you get an alarm.  Wipe it off, then place it on a wet napkin to note the reading.
6. Make sure the sensor is installed on an insulated surface.  If the sensor is to be placed on a metal surface, such as inside an a/c's condensation tray, place a vinyl floor tile under the sensor, in between the sensor and the metal.