A method for correcting systematic error in PO2 measurement to improve measures of oxygen supply capacity

An organisms oxygen supply capacity () 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 PO2 where 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 used post hoc to diagnose error in, correct the magnitude of, and reduce the variability in repeat measures of the oxygen supply capacity.