METHOD AND INSTRUMENT FOR MEASURING INFRARED RADIATION

摘要

PURPOSE:To reduce the size of a modulating equipment by oscillating the optical center of a condenser optical system to make incident the radiation light from a measuring point and a reference point alternately on a detector and determining the radiation intensity at the measuring point from the difference between the high and low levels thereof and the radiation intensity at the reference point. CONSTITUTION:An electromagnetic coil 7 connected to a rectangular wave oscillator 6 is made correspondent with a ferromagnetic material 8 attached to a lens 3 and the center of the lens 3 is made movable between points M and N in the stage of detecting the IR rays from the measuring point A with the detector 4 via the lens 3. The IR rays from the point A while the center of the lens 3 exists at the point M are converged to the point D of the detector 4. The reference point B of the known radiation intensity is provided on the extension of DN from the point A in the direction perpendicular to the optical axis AD thereof. The optical center of the lens 3 is oscillated between the points M and N so as to have the component perpendicular to the optical axis AD. The output difference between the high and low levels from the points A and B is detected by the detector 4 and the radiation intensity of the point A is calculated.