TY - JOUR
AU - Pragnell, R F
AB - Dew and frost formation on the condensation dewpoint hygrometer by R F Pragnell Sira Test & Certification Ltd, Chislehurst, Kent Introduction a Peltier cooler is used to cool a mirror. Normal operation Formation of dew (or frost) on the mirror It is now almost universally accepted surface is detected by means of an optical At near ambient humidities (say 0­ by the standards laboratories of the world sensor and the rate ofcooling is controlled 40°C dp ) the instrument cools the that the condensation dew point to maintain a constant dew layer. The detector surface (usually a mirror) un­ dew may be detected by other methods, til dew forms. The temperature is then hygrometer is the besttype of instrument including capacitance change and sonar. controlled to keep the amount of con­ available for use as a laboratory transfer A temperature sensor, normally a standard. It is used by almost all densate constant. platinum resistance thermometer, is used Initially, the dew has a white misty hygrometer calibration laboratories as the reference instrument for the calibration to measure the condensation temperature. appearance, but usually there is a ten­ ofother types ofhygrometer, and even for More detail is given in an earlier 
TI - Dew and Frost Formation on the Condensation Dewpoint Hygrometer
JF - Measurement and Control
DO - 10.1177/002029409302600803
DA - 1993-10-01
UR - https://www.deepdyve.com/lp/sage/dew-and-frost-formation-on-the-condensation-dewpoint-hygrometer-3RCb70kIFO
SP - 242
EP - 244
VL - 26
IS - 8
DP - DeepDyve
ER -