Quantification of UV-induced erythema with a portable computer controlled chromameter.

A sensitive computer controlled tristimulus color analyzer (Minolta Chromameter II Reflectance) was used to measure UV-induced erythema quantitatively. Of the 5 available chromaticity measuring modes in the instrument, one of the values (a*) was enough to specify the erythema quickly. A comparison has been made between results using the instrument and a graded score based on visual perception of erythema. This easy to operate instrument is suitable for both clinical and field conditions.