Wordnet 3.0
ADJECTIVE (1)
1. 
 of or relating to thermometry; 
- Example: "helium gas was the thermometric fluid"
The Collaborative International Dictionary of English v.0.48:
Thermometric \Ther`mo*met"ric\, Thermometrical
\Ther`mo*met"ric*al\, a. [Cf. F. thermom['e]trique.]
   1. Of or pertaining to a thermometer; as, the thermometrical
      scale or tube.
      [1913 Webster]
   2. Made, or ascertained, by means of a thermometer; as,
      thermometrical observations.
      [1913 Webster]
WordNet (r) 3.0 (2006):
thermometric
    adj 1: of or relating to thermometry; "helium gas was the
           thermometric fluid"