The Collaborative International Dictionary of English v.0.48:

Gravimetric \Grav"i*met"ric\, a. (Chem.)
   Of or pertaining to measurement by weight; measured by
   weight. -- Grav"i*met"ric*al*ly, adv.
   [1913 Webster]

   Gravimetric analysis (Chem.), analysis in which the amounts
      of the constituents are determined by weight; -- in
      distinction from volumetric analysis.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gravimetric
    adj 1: of or relating to hydrometry [syn: hydrometric,
           gravimetric]