Process measuring device for use in e.g. process automation, has comparison part for comparing actual spectrum with reference-frequency spectrum when actual spectrum differs from reference spectrum around predetermined measure

摘要

The device has a measuring unit (1) converting physical or chemical parameter (2) into electrical measuring signal (3), and a signal preprocessing device (5) for digitizing the signal to a digital signal (9). A signal processing device (10) detects the digital signal through multiplication with a reference signal (14) and has a monitoring unit (18) for determining actual frequency spectrum of the digital signal. A comparison part (20) has the actual spectrum with a reference-frequency spectrum when the actual spectrum differs from the reference spectrum around a predetermined measure. The measuring unit is designed as a nondispersive infrared gas analyzer.