calorimeter

views updated May 11 2018

calorimeter (bomb calorimeter) An instrument for measuring the amount of oxidizable energy in a substance, by burning it in oxygen and measuring the heat produced. The energy yield of a foodstuff in the body is equal to that obtained in a bomb calorimeter only when the metabolic end‐products are the same as those obtained by combustion. Thus, proteins liberate 5.65 kcal (23.64 kJ)/g in a calorimeter, when the nitrogen is oxidized to the dioxide, but only 4.4 kcal (18.4 kJ)/g in the body, when the nitrogen is excreted as urea (which has a heat of combustion equal to the ‘missing’ 1.25 kcal (5.23 kJ)).

calorimeter

views updated May 29 2018

calorimeter Any of various devices used to measure thermal properties, such as calorific value. See bomb calorimeter.

calorimeter

views updated May 17 2018

calorimeter (kal-er-im-it-er) n. any apparatus used to measure the heat lost or gained during various chemical and physical changes. Calorimeters are used to determine the energy value of different foods.
calorimetry n.