The Collaborative International Dictionary of English v.0.48:

Acidimetry \Ac`id*im"e*try\, n. [L. acidus acid + -metry.]
   (Chem.)
   The measurement of the strength of acids, especially by a
   chemical process based on the law of chemical combinations,
   or the fact that, to produce a complete reaction, a certain
   definite weight of reagent is required. --
   Ac`id*i*met"ric*al, a.
   [1913 Webster]

WordNet (r) 3.0 (2006):

acidimetry
    n 1: volumetric analysis using standard solutions of acids to
         measure the amount of a base present