From Glossary of Meteorology


An instrument designed by A. F. Dufton in 1929 to record the warmth of a room from the point of view of comfort. It consists of a blackened hollow copper cylinder heated by a carbon filament and a metal filament lamp, which are controlled by a thermostat to maintain a temperature of 75°F. The power used is interpreted in terms of equivalent temperatures.

Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.