Moisture sensors

Filtertechnik offer two types of water sensors for determining the quantity of water in oils, fuels and biofuels; our RH sensors and our WMS500 PPM sensors


RH Water Monitor:
Our RH (Relative Humidity) water monitor gives the percent saturation of a given fluid. 100% saturation is the point at which suspended water becomes harmful free water. These sensors are lower cost and are very useful for hydraulic applications. Outputs are scaled and 4-20mA.

WMS500 PPM Sensor:
Our Genuine PPM sensors are highly accurate parts per million (PPM) sensors and are particularly useful for transformer oils and diesel fuels or biofuel. The sensors are calibrated to a Karl Fischer device and fully temperature compensated.

To understand the different relationships between %RH and PPM please see below:

Parts per million (ppm)

Our PPM sensor gives a count of the absorbed water up to the saturation point of a given oil or fuel. Beyond the saturation point the sensor 'locks out' as free water will have formed.

Relative humidity:

Relative Humidity or RH is expressed as a percentage. 100% RH equates to the maximum amount a given oil or fuel can hold (absorbed water) before it becomes saturated and free water forms.

To view all our quality control and instrumentation click here