Lucimetri

Gloss meters provide objective measurements of surface shine by measuring light reflected at a specified angle.

Results are expressed in gloss units (GU), allowing users to compare finishes, establish acceptance limits and check consistency between samples or production batches. Common applications include paints, protective coatings, plastics, printed materials, furniture and automotive finishes.

Choosing the Right Measurement Angle

The measurement angle determines how effectively a gloss meter distinguishes differences in surface finish.

Measurement AngleTypical Use20°High-gloss surfaces where small differences are harder to distinguish at 60°60°General-purpose measurements across a broad range of finishes85°Low-gloss and matte surfaces requiring greater sensitivity

A 60° measurement is generally the starting point. Surfaces reading above approximately 70 GU at 60° are typically evaluated at 20°, while surfaces below approximately 10 GU are typically evaluated at 85°. Single-angle meters suit routine testing of similar finishes, while multi-angle meters provide flexibility across different surface types.

Applications and Quality Control

Gloss measurements help assess finish uniformity, compare incoming materials and monitor changes caused by polishing, curing, wear or surface treatment. They are particularly useful for identifying differences between production lots and checking whether a finished surface meets an established appearance specification.

Gloss is distinct from color, surface roughness and coating thickness. Products with matching colors can have different gloss levels, so gloss measurement complements other inspection methods when evaluating overall finish quality.

Getting Consistent Results

Measure clean, dry surfaces and keep the instrument orientation consistent, especially on textured or directionally finished materials. Take readings at several locations to assess variation rather than relying on a single measurement. The measurement aperture should fit entirely within the test area, and curved surfaces require an instrument or fixture suited to their geometry.

Check the meter against its reference standard according to the manufacturer’s instructions. When selecting an instrument, consider measurement angles, aperture size, repeatability, measurement range, data storage and reporting capabilities.3nh offers a variety of handheld and benchtop Gloss Meters for testing and quality control.