Significance and Use The chromaticity of the stripe is determined by means of the tristimulus values X, Y and Z for the CIE 1931 (2°) standard observer for CIE Standard Illuminant D65, which are converted to the chromaticity coordinates (x, y) and shown in the CIE 1931 (x, y)-chromaticity diagram. Refer to Practice E 308. Under the same conditions of illumination and viewing, the chromaticity coordinates (x, y) represent the daytime color of pavement markings in daylight illumination as seen by drivers of the vehicles. The chromaticity of pavement (road) markings may change with traffic wear and require periodic measurement to ensure that the chromaticity is maintained within boundaries (see Specification D 6628 for examples of color boundaries). As specified by CEN, the measurement geometry of the instrument is based on a viewing distance of 30 m and an eye height of 1.2 m. It shall be the responsibility of the user to employ an instrument having the specified illumination and co-viewing angle.Scope1.1 This test method covers measurement of the daytime chromaticity coordinates (x, y) of horizontal pavement markings, such as traffic stripes and surface symbols, and pavement surfaces under diffuse illumination, using a portable reflection colorimeter that can be placed on the surface to measure the chromaticity in a particular viewing direction.1.2 The co-viewing angle of the reflection colorimeter affects the readings. As specified by the European Committee for Standardization (CEN EN 1436), the co-viewing angle shall be 2.29.1.3 This test method is intended to be used for field measurement of pavement markings but may be used to measure the chromaticity and the luminance coefficient under diffuse illumination of materials on sample panels before placing the marking material in the field.1.4 The portable reflection colorimeter may integrate measurement of the luminance coefficient under diffuse illumination Qd according to Test Method E 2302 and thus be an integrated reflectometer/reflection colorimeter.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.
