AN AUTOMATICALLY COMPENSATING HEAT-EXCHANGE CALORIMETER FOR METABOLIC STUDIES

This paper describes an easily constructed calorimeter functioning on a heat-exchange principle in which a continuously flowing coolant removes heat at a preset rate. Variations in heat loss from an experimental animal are compensated by a resistance hot wire in a simple feed-back circuit so that calorimeter temperature is held constant. Accommodation for simultaneous measurement of oxygen consumption (heat production) is included. Agreement between steady-state heat loss and heat production determined by these two means agrees usually within 5 per cent. The simplicity of the equipment permits a wide variety of physiological tests in various combinations to be performed simultaneously with direct calorimetry. © 1968 International Federation for Medical and Biological Engineering.