PURPOSE: To enhance measuring accuracy, by detecting the transmission quantity of an electromagnetic wave of each wavelength in the mode fitted to the magnitude thereof.
CONSTITUTION: In a phase of one cycle, a detection controller 3 takes out a mode initially set with respect to a wavelength from a memory 9 and the gain of a photomultiplier tube 58 is adjusted according to said mode by a control signal CTL' and a switch SW is changed over by a selection signal SL. By this method, since transmission quantity can be measured in the mode corresponding to the transmission quantity of the light incident to the photomultiplier tube 58, a measuring result can be obtained with good accuracy without cutting off transmission quantity data at all even when transmission quantity is much.
YAGI SUMIO
OZAKI TAKEO
HAKAMATA NAOTOSHI
