Colour pyrometer for temp. determination of rolled metal - has compensation channel with adjusted time constant to provide higher operating rate

摘要

The colour pyrometer has the focussed input beam (2) divided into individual light currents (7,8,9) with different wavelength ranges fed to respective measuring ranges channels (13,14,15). Each of these has an input photodetector (10,11,12) coupled via a signal matching element (16a,16,24) and a variable voltage divider (17a,17,25) to an amplifier (20a,20,28) and a comparator (21a,21,30). One of the measuring channels (15) has a variable voltage source (35) feeding a signal to the frequency divider (25) for this channel in dependence on a control signal supplied by a threshold device (36). This receives the output of the photodetector (12) via the signal matching element (24). The pyrometer is used to determine the temp. of the product during hot rolling.