Patent ID: 8445847
Filing Date: 2013-05-21
Classification: G01J

Abstract:
1. A measurement abnormality detection device for an infrared radiation thermometer for measuring a casting mold, comprising: a dummy lens placed around an objective lens of the infrared radiation thermometer and arranged close to the objective lens and above the mold, the dummy lens facing more downward than the objective lens so as to be more susceptible to adherence of contaminants emitted from the mold and thus to more contamination than the objective lens; a laser displacement meter that projects a light to the dummy lens at predetermined intervals or at a predetermined timing, and receives the light reflected by the dummy lens, and measures a received light quantity; and a determination device that is programmed to calculate an attenuation rate of the projected light on the basis of the received light quantity measured by the laser displacement meter, estimate a degree of contamination of the dummy lens on the basis of the calculated attenuation rate, and judge necessity of warning for contamination of the objective lens on the basis of the degree of contamination of the dummy lens, wherein the dummy lens and laser displacement meter are constructed independently from the objective lens.