cal·o·rim·e·ter 
(kăl′ə-rĭmĭ-tər)
(kăl′ə-rĭmĭ-tər)n.
An apparatus or container for measuring the heat generated by a chemical reaction, change of state, or formation of a solution.
[Latin calor, heat; see kelə-1 in the Appendix of Indo-European roots + -METER.]
ca·lor′i·metric (kə-lôr′ə-mĕtrĭk, -lŏr′-) adj.
ca·lor′i·metri·cal·ly adv.