An Automatic Correction Circuit for Respiratory Mass Spectrometers

Abstract

An automatic correction circuit has been developed for improving the precision of mass spectrometric continuous analysis of the respiratory gases. The principle of correction is based on the fact that most of the variation factors occurring in the direct inlet system are canceled away together with many of variations occurring in the ion source and electronic measuring system by rationing the raw outputs of the mass peaks. The correction circuit has four functions, i. e. compensation of the overlapping peaks, equalization of the overall sensitivities of the relevant components, rationing the each peak to the sum of the relevant peaks and settlement of the total pressure. Through these processings, the output is expressed in pressure. The method is inapplicable to a continuous analysis of the condensable gases because of their slower response of transmission.The precision of the analysis proved to be maintained within 1%for natural dry gases unless the sample flow in the inlet process is extremely disturbed.