| 摘要 |
PURPOSE:To improve an SN ratio in a spectrum measuring device using line image sensors by splitting a wavelength region according to the output levels of measuring light, and changing the integrated time of the output in correspondence to these. CONSTITUTION:The light diffracted with the concave diffraction grating G of a spectroscope 1 is imaged on a photodiode array P driven by a sweeping circuit 2 and the output thereof is inputted and stored in a control circuit 3 via a preamplifier 4 and an ADC5. The photometric value thereof is segmented to plural numbers of partial wavelength regions and the ratios of the max. value of the measured values in the respective partial region to the satd. output value of the photodetectors P are calculated and the scanning speed of the circuit 2 is controlled until the ratios thereof attain 1. In this state, the transmittance is measured, whereby the SN ratio is improved. |
