| 摘要 |
<p>PURPOSE:To provide a photodetector capable of obtaining the accurate informa tion without being influenced by difference of characteristics of individual photodetectors and temperature drift thereof in terms of a light from an object to be measured, of which position or condition is varied. CONSTITUTION:A reflection light that is emitted from a light source 13 and is reflected after penetrating an object 12 to be measured is divided into a plurality of optical paths 15a, 15b by a beam splitter 21 and a mirror 22. Combinations of optical filters 24, 25 and photoelectric conversion devices 35, 36 are sequentially exchanged against each divided light by means of the optical filters 24, 25 mounted on a rotational disk 23. An absorbance calculating circuit 40 calculates absorbances in terms of the respective combinations of the optical filters 24, 25 and photoelectric conversion devices 35, 36 in order. The calculated absorbances are stored in a memory circuit 41 and an averaging circuit 42 averages the plural absorbances to indicate the average value on an indication device 43.</p> |
