Chilled mirror hygrometer Model CMH
Self contained dew point hygrometers combine the inherent accuracy, reliability and long term stability of optical chilled mirror technology, with the convenience and ease of use needed in industry
These self contained dew point hygrometers combine the inherent accuracy, reliability and long term stability of optical chilled mirror technology with the convenience and ease of use of demanded by Industry. The Model CMH dewpoint hygrometers are designed for continuous monitoring applications where high accuracy and reliability are required. Dewpoint temperature measurement is made using a direct measuring sensor utilising a Peltier-cooled mirror, automatically held at the dew point temperature by a condensate detecting optical system, incorporating an LED light source and photo-detector.
The optical sensing bridge detects the change in light level when dew or frost forms on the mirror.
Subsequent cycles of negative feedback controlled heating and cooling refine the result to a highly accurate constant reading of sample dew point.
This technique is a primary measurement of the water vapour content of the gas.The mirror temperature represents the true dew point temperature and is measured by an embedded precision platinum resistance thermometer.
For dew points below 0C, the instrument displays the frost point.