Hygrometers

Hygrometer - a measuring device for determining the air humidity.

Electronic hygrometer may use different principles:

- Optoelectronic - measuring dewpoint by means of a cooled mirror (mirror frozen, then gradually heated, and is determined by dew point);
- fluid - the change in capacitance is measured, or polymeric metaloksidnogo capacitor (measured only from 5% to 95%, aging, but almost independent of temperature);
- resistance - using the effect of changing salt conductivity or conductive polymers, depending on the humidity
- measuring the conductivity of air (absolute humidity is measured to calculate the relative humidity is also required temperature measurement).