Radiometer

A radiometer for scanning a background comprising:

• an optical drive system;
• at least one curved mirror element integral with said optical drive system and directing thermal radiation;
• a detector facing said mirror element at a distance and receiving the directed thermal radiation;
• electronic means for performing a weighting evaluation corresponding to the position of detectors;
• a display unit, a threshold value indicating the degree of radiation of the observed object on said display unit;
• said optical system together with said detectors being located about axes containing the center of curvature of said curved mirror and being rotatable in steps or continuously;
• said mirror having the shape of at least a segment of a hollow sphere;
• said mirror having an entry window and a boundary with a funnel-shaped expansion from said entry window and towards said mirror, a modulator disk having a mirror-coated side facing said detectors and located on the outside in front of said entry window;
• a first housing for holding said optical system and said electronic means;
• a second housing holding said first housing, a power supply, cleaning means for said entry window;
• means for driving said modulator disk together with said radiometer;
• said electronic means within said first housing comprising detector strip means;
• preamplifier means connected to said detector strip means;
• multiplexer means connected to outputs of said preamplifier means;
• an output series circuit connected to the output of said multiplexer means;
• a first comparator receiving one input from said series circuit;
• first storage means connected to a second input of said first comparator means;
• a first counter for counting timing pulses and connected to the output of said first comparator means, said first storage means applying a threshold value to said second input of said first comparator means;
• second comparator means having one input connected to the output of said first counter;
• second storage means connected to a second input of said second comparator means, said second comparator means comparing the output of said first counter and the output of said second storage means and passing a number of timing pulses corresponding to the weighting evaluation;
• a second counter connected to the output of said second comparator and receiving said number of timing pulses corresponding to the weighting evaluation and passing a number of timing pulses corresponding to the degree of radiation;
• a third counter controlled by said number of timing pulses from the output of said second counter, the output of said second counter being connected to the output of said third counter;
• display means connected to the output of said third counter.