ASTM E1349 Reflectance Factor and Color by Spectrophotometry Using Bidirectional Geometry

Scope:

This ASTM E1349 test method is notably useful for determining the color of object-color specimens of any gloss level. Data for computer colorant formulation can be obtained from object-color specimens with physically flat, smooth surfaces and for Specimens that are retroreflective.

Procedure:

When specimens have directionality and a uniplanar instrument is utilized, information on directionality is retrieved in the ASTM E1349 test by measuring the specimens at multiple rotation angles, usually two 90° angles apart. The specimen is placed against the integrating sphere’s reflectance measuring port, using supporting material. Following the manufacturer’s instructions, the specimen is measured. Parallel and perpendicular to the machine, a specimen at two 90° rotation angles are measured.

Video 01: Spectrophotometer

Specimen size:

Translucent specimens with two essentially plane and parallel surfaces and standard thickness and opaque specimens with at least one plane surface are used in ASTM E1349 testing.

Data:

When measuring directionality in specimens using instruments with uniplanar geometry at two or more rotation angles, average the instrumental data for all rotation angles observed.

Conclusion:

Any nonfluorescent, flat object-color specimen can be tested using this ASTM E1349 procedure. It’s especially useful for measuring retroreflective specimens and intermediate-gloss specimens.