再帰性反射材料の再帰反射分光係数の測定
1994 年 78 巻 6 号 p. 284-292
詳細
1994 年 78 巻 6 号 p. 284-292
An apparatus has been designed to measure the spectral coefficient of retroreflection of materials used for traffic signs under nighttime geometric conditions.
This paper describes the configuration of the apparatus and its performance, and also gives an estimate of accuracy in the measurement of the spectral coefficient of retroreflection by means of the apparatus.
A small integrating sphere is used to overcome the geometric conditionof small observation angle and to eliminate the error due to polarization effect in the optical system. Retroreflected light from thesample is effectively collected by the sphere, and transferred to a double monochromator through an optical fiber bundle.
It is estimated that the accuracy in the spectral coefficient of retroreflection is better than ±1%.
The measurement results obtained by the use of the apparatus are presented, where the typical retroreflective materials have been prepared for the international inter comparison measurement conducted by CIE TC-2.19.
