The Collaborative International Dictionary of English v.0.48:

Volumeter \Vo*lu"me*ter\, n. [Cf. F. volum[`e]tre. See
   Volumetric.] (Physics)
   An instrument for measuring the volumes of gases or liquids
   by introducing them into a vessel of known capacity.
   [1913 Webster]

WordNet (r) 3.0 (2006):

volumeter
    n 1: a meter to measure the volume of gases, liquids, or solids
         (either directly or by displacement)