A computer controlled calibrator, spectrum overlap eraser and automatic sensitivity control for an anaesthetic mass spectrometer.
The operation, design and performance of a microcomputer controlled spectrum overlap eraser and automatic sensitivity control (ASC) for a clinical mass spectrometer are described allowing calibration for up to eight anaesthetic gases in less than 15 s per gas. The critical design parameters are identified and the mathematical algorithm used discussed. Constructional details of the system are given with particular reference to the key components identified in the analysis of design parameters. The results of static and dynamic testing of the system are reported. The calibrator showed output linearities within +/- 1.7% first standard deviation (FSD) for a two part mixture of gases relevant in anaesthesia and a typical accuracy of 2.1% FSD for any point. Dynamic testing showed that the machine did not impede the overall speed of response of the system. Transient viscosity effects were adequately eliminated and ASC action effective for variation in source pressure between 11.3 X 10(-3) Pa and 2.7 X 10(-4) Pa. Mean drift with the calibrator was found to be less than 0.38% vol/vol h-1.
D000776:Anesthesiology / Q000295:instrumentation*; D002138:Calibration; D004559:Electric Wiring; D005069:Evaluation Studies as Topic; D006801:Humans; D013058:Mass Spectrometry / Q000295:instrumentation*; D008433:Mathematics; D008838:Microcomputers; D012984:Software