Humidity measurement mechanical hygrometer

Mechanical Hygrometers Materials such as human hair, wood fiber, and plastics have been used to measure humidity. These methods rely on a change in dimension with humidity. 

These methods use mechanical probes or hygrometers that respond to the variations in the relative humidity of air that are caused by variations in dielectric resistance or capacity. These probes directly measure the relative humidity of air, and the most commonly used is lithium chloride. In general, these methods require frequent calibration and should only be used within a narrow range. 

The main types of instruments measuring humidity in gases are various types of hygrometers (gravimetric, mechanical, condensation, infrared absorbance detector, electric sensor, thermal conductivity, Al203/sili-con, P2O5) and psychrometers. 

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