Static and dynamic accuracy required of gas concentration measuring instruments.

The dynamic and static accuracy required of gas concentration measuring instruments for the measurement of physiological parameters is discussed. Static accuracy is examined using error sensitivity analysis of a range of physiological measurements requiring gas concentration information. From this an acceptable static accuracy of +/- 0.1 per cent volume/volume is established as an acceptable accuracy. Dynamic accuracy is examined using an idealised exhaled carbon dioxide curve. By considering the contribution of various features in the curve to the power spectrum of the curve a 'rule of thumb' for acceptable dynamic bandwidth of acceptable bandwidth = 4 (heart rate/60) + 5 Hz where heart rate is in beats min-1, is developed.