1.1 This test method covers an instrumental procedure for quantifying the degree of dirt collection on exposed exterior coated panels.

1.2 This test method is limited to those coated exterior panels with lightness values before exposure significantly greater than those after exposure.

1.3 The instrumental readings do not distinguish between mildew growth and other forms of dirt.

1.4 This test method measures total dirt collection. Loose dirt may be washed and removed from specimens if only imbedded dirt collection is to be measured.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.