| 摘要 |
PURPOSE:To improve measuring accuracy, by automatically controlling the utilization of amplifiers so that a reference light signal becomes maximum within a range an A/D converter, to which the reference light signal is inputted, is not overflowed. CONSTITUTION:A reference light signal Er is used in a measuring device as a reference signal. In this device, a gain N of amplifiers 22 and 82, which amplify the output signal Er from a reference light receiving element 12, is controlled by a counter 7 through switch groups 62 and 92, so that the reference light signal Er becomes maximum within the range an A/D converter 42 is not overlowed. In this constitution, the effects of the receiving sensitivity of the light receiving element 12, intensity fluctuation of a light source, and the like are removed, and the high measuring accuracy is always obtained. |
