METROLOGY, DOCUMENTARY STANDARDS, AND COLOR SPECIFICATIONS FOR FLUORESCENT MATERIALS

Some aspects of the metrology of fluorescence are reviewed. ASTM Commi ttee E-12 on Appearance has written two documentary standards on the i nstrumental measurement of fluorescent colors. Test Method E 1247 prov ides two procedures for detecting small amounts of fluorescence that m ight affect the measurement or use of nominally nonfluorescent materia ls. Practice E 991 deals with the measurement of specimens meant to be viewed under standard natural daylight, and that, therefore must be i lluminated by a good instrument daylight simulator. Two procedures are given for assessing the suitability of the simulator, and the require d instrument geometry is specified. A future ASTM standard is under co nsideration that would describe methods for correcting the data obtain ed with another instrument source to the data that would have been obt ained with standard daylight illumination. Two groups of standard spec ifications exist for fluorescent colors used for signaling or safety e nhancement. One defines suitable chromaticities for both red and orang e colors (among others), but ignores the fact that these colors cannot always be obtained with good lightfastness by use of existing pigment s. The other group provides instead a red-orange specification for whi ch specimens with good lightfastness can be obtained. The relative mer its of the two groups are discussed. (C) 1994 John Wiley and Sons, Inc .