Use of the Pauling Oxygen Analyzer for Measurement of Oxygen Consumption of Animals in Open-Circuit Systems and in a Short-Lag, Closed-Circuit Apparatus

Abstract

A basic formulation of methods of obtaining oxygen consumption data from measurements of oxygen partial pressure in open and closed-circuit systems is made. For open-circuit systems used in the steady state, equations are given and discussed for the following cases in which the stated variables are measured: 1) inlet air volume and Po₂, and outlet air Po₂; 2) inlet air volume and Po₂, and CO₂ free outlet air Po₂; 3) outlet air volume and Po₂, and inlet air Po₂; 4) CO₂ free outlet air volume and Po₂, and inlet air Po₂. An approximate equation has been obtained for an open-circuit system used under nonsteady state conditions for the special case of a metabolism chamber of large volume. A constant volume, closed-circuit system having a very small lag is also described in detail and data are provided to illustrate its time response and to show that the system yields true values of oxygen consumption. Submitted on September 14, 1956