Electronic – this component from an old thermostat

components

I recently cannibalized an old thermostat for parts, and found a strange looking component with no markings at all.

Here's a picture (since I can't figure out how to describe it):

photo of part

My first guess was that this was some sort of resistor, but I can't seem to measure any resistance across it with my multimeter…

I'm very much an electronics newbie so please excuse me if the answer is obvious 🙂

Best Answer

It's a resistive hygrometer (or simply put: a humidity sensor). The resistance across the contacts varies depending on the relative humidity of the air it is suspended in.

Example from TDK

Related Topic