| 摘要 |
PURPOSE:To obtain an instrument enabling to perform accurate measurement even if the ambient temperature is changed by inserting an optical rotatory power element into an optical sensor part. CONSTITUTION:The emission wavelength of light from an optical transmitter 1 is changed by its ambient temperature and the light intensity modulation is made by the quantity to be measured by a polarizer 4, a Faraday element 5 and an analyzer 6 constituting the optical sensor part but since a Verdet's constant of the Faraday element 5 has wavelength dependency, the modulation sensitivity is changed by the temperature of the transmitter 1. Then, since the modulation sensitivity at the optical sensor part is made always constant even if the wavelength of the transmitter 1 is changed by providing the optical rotatory power element 15 having the wavelength dependency contrary to said wavelength dependency between the polarizer 4 and the analyzer 6, the accurate measurement is made possible. In this case, the magnitude and porality of the wavelength dependency of the Verdet's constant of the Faraday element 5 and the wavelength dependency of the optical rotatory power element 15 can be freely canceled by selecting properly a relative angle of the plane of polarization of the polarizer 4 with the analyzer 6. |
