BS EN 60068-2-70. Environmental testing - Part 2-70. Tests. Test Xb. Abrasion of markings and letterings caused by rubbing of fingers and hands included-in-kit yttrium (Y)

yttrium (Y)

amara (DC) Focke

with the movement generated by a screw thread

The formula is an extension of the CIE 1976 L*a*b* colour-difference formula (ISO 11664- 4:2008(E)/CIE S 014-4/E:2007) with corrections for variation in colour-difference perception dependent on lightness

NOTE 1 An operative attending non-domestic premises might be required to examine standard gas-fired appliances which are domestic or commercial as well as customized process plant/equipment

BS EN 60068-2-70. Environmental testing - Part 2-70. Tests. Test Xb. Abrasion of markings and letterings caused by rubbing of fingers and hands included-in-kit yttrium (Y)