COMPARISON BETWEEN VISUAL GRADING AND REFLECTANCE MEASUREMENTS OF ERYTHEMA PRODUCED BY SUNLIGHT

[摘要] In developing methods of skin color measurement to substitute for verbal descriptions or rating scales, we can set as our goal the development of methods which provide parallel columns of 2 or 3 digit numbers for evaluation by standard statistical methods. The photoelectric reflectance meter with appropriate filters and standards appears to meet this desideratum. In this report we have presented our rationale, and correlation studies on skin reflectance readings and parallel visual grading of skin made erythe-matous or tanned by sunlight exposure. On the basis of this experience our current recommendation for filters for analyzing skin color is as follows: A sample of the blue region of the visible spectrum should be obtained by an interference filter; a transmittance maximum of about 460 millimicrons would appear desirable. An interference filter with a transmittance maximum at 542 or 576 [mu] should be used for maximum response to oxyhemoglobin. Either an interference filter with transmittance maximum between 620 and 660 [mu] or a red glass filter (such as Corning glass No. 2403) should be used to sample the region in the red end of the visible which depends primarily upon melanin, although some effect from oxyhemoglobin and reduced hemoglobin cannot be avoided.