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a thermometer with a wet bulb and a dry bulb, for detecting cooling rates.
An alcohol-filled thermometer of specified design that is heated above ambient temperature and then allowed to cool; the time taken to cool between specified temperatures is a measure of the heat content of the environment that takes into account air movement as well as temperature. The bulb may be silvered to minimize radiation effects or blackened to maximize them.
katathermometer(kăt″ă-thĕr-mŏm′ĕ-ter) [″ + therme, heat, + metron, measure]
A device consisting of two thermometers, one a dry bulb and the other a wet bulb. Both are heated to 110°F (43.3°C) and the time required for each thermometer to fall from 100° to 90°F (37.8° to 32.2°C) is noted. The dry bulb gives the cooling power by radiation and convection, the wet bulb by radiation, convection, and evaporation.