oxycalorimeter

ox·y·cal·o·rim·e·ter

(ok'sē-kal'ō-rim'ĕ-tĕr),
A calorimeter measuring energy content of substances in terms of oxygen consumed.

oxycalorimeter

[ok′sēkal′ôrim′ətər]
an apparatus that measures the heat of combustion of organic materials in terms of oxygen consumed. Each liter of oxygen is roughly equivalent to 5 kilocalories.