I am trying to identify this electrical component at my work, it acts a leak detection sensor on a pump that when exposed to water will shut down the system.
Thank You !
Electronic – this component
identificationsensorwater
identificationsensorwater
I am trying to identify this electrical component at my work, it acts a leak detection sensor on a pump that when exposed to water will shut down the system.
Thank You !
Best Answer
There is a good chance that you have a pair of thermistors there. They can function as a liquid detector as follows:
Bias both thermistors equally so that enough current flows through each thermistor to cause it to heat up. This is called "Self-Heating".
Allow one thermistor be able to be contacted by the liquid, protect the other thermistor so that liquid can't touch it.
Monitor the voltage across each thermistor. When both are in free-air, the voltage drop will be similar. Note that ambient temperature changes drop out of the equation because both thermistors are exposed to the same ambient temperature.
When liquid touches one of the thermistors, it cools off and its resistance changes. By comparing the voltages from each thermistor, it is very easy to see when liquid touches one of them.
The circuit can be very simple - ranging from a single transistor to 2 or 3 transistors.
Simple, inexpensive, and (usually) very reliable.