Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

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