<i>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</i>

TLDR

The study formulates a basic method for deriving oxygen consumption from oxygen partial pressure measurements in both open‑ and closed‑circuit systems. Equations for steady‑state open‑circuit systems are presented for four measurement configurations involving inlet/outlet air volume and Po₂, with or without CO₂‑free outlet air. An approximate equation for nonsteady‑state large‑volume open‑circuit chambers is derived, and a constant‑volume, short‑lag closed‑circuit system is shown to produce accurate oxygen consumption values and a predictable time response. The manuscript was submitted on September 14, 1956.

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