Which conditions must not be wrong when you measure color-difference deviation
This 5 is valid only under the agreed geometry, M condition, illuminant, and the same backing. Change any one and you cannot use 5 to call a pass.
This 5 is valid only under the agreed geometry, M condition, illuminant, and the same backing. Change any one and you cannot use 5 to call a pass.
Which conditions have to hold together
Do not treat ΔEab 5 as the variation allowed from sheet to sheet. Variation uses another set of numbers, not this rule. If the conditions differ, the two numbers cannot be compared.
Condition check
| Item | Do this | Do not |
|---|---|---|
| Color-difference deviation | This 5 is valid only under the agreed geometry, M condition, illuminant, and the same backing. Change any one and you cannot use 5 to call a pass. | Only write a feeling |
| The common mistake | Do not treat ΔEab 5 as the variation allowed from sheet to sheet. Variation uses another set of numbers, not this rule. | Leave the mistake in place |
| What to keep | The report must state ΔEab, which signed sample it is against, the M condition, the geometry, and the backing. If any one is missing, do not call it a pass. | Only leave the word passed |
Check before you measure
- First see whether the contract says deviation or variation.
- Note the geometry, the M condition, and the backing.
- Compare only two readings taken under the same conditions.
