Question

What are transducers? Explain how a polymer capacitor is used as a humidity transducer.

Answer 1

Transducers are devices that convert energy from one form to another. It converts variations in a physical quantity e.g. brightness of light into electrical signal etc.

In a Humidity Sensor, a small capacitor made up of a hygroscopic dielectric material is placed between two electrodes. The dielectric material used is mostly made of polymer. When the sensor does not detect any humidity, the constant and the sensor geometry determine the value of capacitance.