an apparatus for measuring high temperatures that uses the radiation emitted by a hot body as a basis for measurement.
Origin of pyrometer
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
an instrument for measuring high temperatures, esp by measuring the brightness (optical pyrometer) or total quantity (radiation pyrometer) of the radiation produced by the source. Other types include the resistance thermometer and the thermocouple
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012