Colour pyrometer control circuit - has outputs from signal reduction channel controlling voltage dividers and switches in measuring channels to decrease overshoot

摘要

The colour pyrometer comprises a lens (1) which forms a narrow light beam from light emitted from an object, and a beam-splitter (5) having different colour filters which directs different spectral ranges onto photodetectors (9-11). One detector (11) forms part of a signal reduction channel including a signal watching circuit (23), a voltage divider (24, 25) and an amplifier (26). Signals above a reference level set by a reference pulse source (28) are sensed by a comparator (27) whose output controls adjustable devices (25, 17) in the voltage dividers of the signal reduction channel (14) and the measuring channels (12, 13) so that the difference sensed by the comparator (27) is nulled. The output of a delay circuit (29) connected to the comparator output is connected to switches (22) in the measuring channels which are controlled so that initial transients are not transmitted to the measuring channel outputs.