| 摘要 |
PURPOSE:To measure a temperature on the basis of the intensity of transmitted light which varies with temperature by making light passed through a polarizer incident on a birefringent crystal element cut slantingly to an optical axis. CONSTITUTION:A light emitting element 2 is driven by a driving circuit 1 to emit light with specific intensity. The light from the element 2 is made incident on the polarizer 5 of a sensor head 4 through an optical fiber. A linear polarized wave extracted by the polarizer 5 is made incident on the birefringent crystal element 6. Further, an optical fiber 8 guides the projection light of an analyzer which is passed through the element 6 to a photodetecting element 9. The output signal of the element 9 is amplified by an amplifier 10 and displayed 11 as a value of temperature. Then, the element 6 is cut slantingly to the optical axis to expand the temperature measurement range between the maximum and minimum of transmitted light, for example, to seven times as large as when the element is not cut slantingly. Therefore, the temperature sensor which has the sufficiently wide temperature measurement range is obtained even when thick birefringent crystal which is worked relatively with ease is used. |
