APPENDIX D
COLOR CHECK
The color check procedure will help you track instrument color
performance to assure measurement accuracy. Initially, the three patches
on the standard should be measured once a day for a period of 10 days to
determine the reference values. Thereafter, a periodic check (once a week
depending on usage) is all that is required.
Located on the back of the reference standard envelope is a color check
label. The reference data should be recorded there for quick reference.
Reference Data Procedure
To obtain reference values:
1) Clean instrument optics and reference standard if necessary.
2) Calibrate instrument according to procedure in operation manual. Note:
The reference standard is dramatically affected by smudge marks and
dust; and must be kept clean.
3) Select L*a*b* absolute function and desired illuminant/observer. Note:
The selected illum/obs must be the same whenever the color check is
performed.
4) Measure the White (1), Blue (2), and Brown (3) patches on the reference
standard.
5) Record the L*a*b* values for each color on a piece of paper.
6) Repeat steps 1-5 for 10 days.
White Blue
Brown
D-1
➩
