Humidity and Moisture Sensors

Abstract

The water content in surrounding air is an important factor for the well-being of humans and animals. The level of comfort is determined by a combination of two factors: relative humidity and ambient temperature. You may be quite comfortable at −30 °C (−22 °F) in Siberia, where the air is usually very dry in winter, and feel quite miserable in Cleveland near lake Erie at 0 °C (+32 °F), where air may contain substantial amount of moisture. Humidity is an important factor for operating certain equipment, for instance, high impedance electronic circuits, electrostatic sensitive components, high voltage devices, fine mechanisms, etc. A rule of thumb is to assure a relative humidity near 50 % at normal room temperature (20–25 °C). This may vary from as low as 38 % for the Class-10 clean rooms to 60 % in hospital operating rooms. Moisture is the ingredient common to most manufactured goods and processed materials. It can be said that a significant portion of the U.S. GNP (Gross National Product) is moisture [1].