PYROMETER
Py*rom"e*ter, n. Etym: [Pyro- + -meter: cf. F. pyromètre.]

1. (Physics)

Defn: An instrument used for measuring the expansion of solid bodies by heat.

2. (Physics)

Defn: An instrument for measuring degrees of heat above those indicated by the mercurial thermometer.

Note: It is usually constructed so as to register the change which the heat to be measured produces in the length of some expansible substance, as a metallic rod, or in the intensity of a thermo- electric current.

PYROMETRIC; PYROMETRICAL
Pyr`o*met"ric, Pyr`o*met"ric*al a. Etym: [Cf. F. pyrométrique.]
(Physics)

Defn: Pertaining to, or obtained by, the pyrometer; as, pyrometrical instruments; pyrometrical measurements.

PYROMETRY
Py*rom"e*try, n.

Defn: The art of measuring degrees of heat, or the expansion of bodies by heat.