PURPOSE: To measure light transmittability with a good sensitivity even with a sample having a large degree of scattering by forming a reflecting surface which reflects the irradiating light to the inside surface in a vessel.
CONSTITUTION: A light receiver 5 is removed from a small window 4 of the spherical vessel 1 and the sample 10 (collooidal soln., such as milk) is put into the sample 1 from the opened small window 4 to entirely fill the inside the vessel; thereafter, the light receiver 5 is mounted to the small window 4 to cap the window. A light source 6 is then lighted to diffuse and radiate light from the front end of an optical bundle 3. The radiated light transmits the inside of the sample 10 and is partly received directly in the light receiver 5. The light radiated from the front end of the optical bundle 3 and is scattered up to the light receiver 5 is irradiated onto the inside surface of the vessel 1 and is reflected repeatedly many times until finally the light is received in the light receiver 5. This light is outputted as a voltage value to an arithmetic unit 9. The value approximate to the true absorbed quantity of the light is thus determined.
SHICHIRI MASATAKA
TSUCHIMOTO MASAAKI
ISHIBASHI HITOSHI
