摘要 |
PURPOSE:To improve the S/N and the space resolution by placing plural infrared detectors without changing a size of a chopper. CONSTITUTION:When a chopper 1 is in a position shown in a figure (a), infrared detectors 2a, 2b receive an infrared light from an object to be measured 5. Subsequently, when the chopper 1 rotates by 90 deg., as for the detectors 2a, 2b, the chopper is closed, and an infrared radiation from the reverse side of the chopper is measured by a platinum resistance thermometer 4. Next, as for infrared detectors 2c, 2d, the chopper is closed, and the infrared light from the object to be measured 5 is received. Outputs of the detectors 2a-2d are added to a signal processing part 8, and also, a measuring output of the ther mometer 4 is added to the processing part 8. In the processing part 8, a refer ence black-body temperature is calculated, based on an output of the thermome ter 4, and by a difference between outputs of each detector 2a-2d and this reference black-body temperature, a temperature of the object to be measured 5 is converted to an absolute temperature, and a phase difference is corrected and added. In this case, by giving phase information for opening and closing the chopper 1 to the processing part 8, the signal processing can be executed surely. |