Source : Webster's Revised Unabridged Dictionary (1913)

Pyrometric \Pyr`o*met"ric\, Pyrometrical \Pyr`o*met"ric*al\ a.
   [Cf. F. pyrom['e]trique.] (Physics)
   Pertaining to, or obtained by, the pyrometer; as,
   pyrometrical instruments; pyrometrical measurements.