The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]