A method for correcting systematic error in PO₂measurement to improve measures of oxygen supply capacity

Abstract

An organism’s oxygen supply capacity (α) can be measured as a ratio of the metabolic rate (MR) and the critical oxygen partial pressure (Pc). However, this metric is sensitive to errors in the measurement of PO2, especially at low PO2where the ratio of instrument error to environmental oxygen is magnified. Consequently, the oxygen supply capacity of animals, particularly those that evolved in low-oxygen environments, may appear unnaturally high and variable. Here, we present a method to correct for instrumental calibration error and use simulated and literature datasets to demonstrate how it can be usedpost hocto diagnose error in, correct the magnitude of, and reduce the variability in repeat measures of the oxygen supply capacity.