title: A comparison between a tristimulus colorimeter (Minolta ChromaMeter CR-200) and two spectrophotometers (Minolta Spectrophotometer CM-508i and CM-2002). Quantification of UV-B induced erythema in a hairless guinea pig model.
abstract: OBJECTIVE
  A comparison was made between a tristimulus colorimeter (Minolta ChromaMeter CR 200) and two spectrophotometers (Minolta CM-508i and CM-2002). The object was to compare skin colour data in the CIE 1976 L*a*d*colour space system obtained with the different instruments after UV-B exposure.
  
  
  METHODS
  Guinea pigs were exposed on their dorsal trunk with UV-B light for different time periods. Skin colour in the L*a*b* system was measured 6 and 24 h after exposure.
  
  
  RESULTS
  Reproducible and objective measurements expressed in the CIE system were obtained with all three instruments. A strong correlation was found between the Minolta Chromameter CR200 and each of the two spectrophotometers. However, absolute values found with the Minolta ChromaMeter CR 200, especially for b*, differed from values obtained with the two spectrophotometers.
  
  
  CONCLUSIONS
  The instruments were, despite minor inter-instrumental variation, suited for objective evaluation of erythema. The spectrophotometers were somewhat cumbersome to use due to their heavy weight and difficulties in positioning within the test sites; the Minolta CromaMeter CR200 (or later versions) is thus preferable for simple routine measurements. Use of the spectophotometers appears only indicated where specific information about skin pigments or photoactive substances relative to wavelength is needed.
authors.affiliation: Department of Dermatologcal Research, Leo Pharmaceutical Products, Ballerup, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Fullerton
authors.affiliation: Department of Dermatologcal Research, Leo Pharmaceutical Products, Ballerup, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Keiding
keywords: Minolta ChromaMeter; colorimetry; comparison; spectrophotometers