The gloss meter is used to measure the gloss level: it is a device that directs the light at a fixed angle and reads the intensity of the reflected light. The angles, such as 60°, 20°, or 85°, are applied depending on the type of surface and the range of gloss.

Record the L*a*b values of the sample and the reference with a calibrated spectrophotometer or colorimeter. Compute the difference in the color by use of ΔE. The lower the Delta E, the more accurate the result. The difference in energy, ΔE < 1, is generally assumed to be invisible to the eye.

An inappropriate viewing angle may lead to reflections or color shifts in the light. The correct angle of 45 or 0 will provide the real color of the assessment without the distraction of glare.

A service is made up of tub replacement, light source recalibration, internal cleaning, verification of service and color certification retention so that all compliance color standards are retained. 

When detecting color differences, the first factors to consider when selecting a light source include its stability, directionality, lifespan, and the effectiveness of the ultimately obtained spectral curve. The illuminant of a colorimeter is a fixed bulb, such as a tungsten lamp，LED light or a long-life xenon lamp. However, for the same color sample, the results displayed by the instrument vary under different light sources. This is because different light sources cause different absorption and reflection of light on the sample, leading to differences in how both the human eye and the instrument perceive the color. 

In general, the D65 light source is used in the application of coil steel inks for construction. The D65 light source is equivalent to average daylight. Most coil steel inks for construction are used outdoors, and sunlight is regarded as the standard light source in outdoor environments. For household appliance coil steel inks, due to their usage characteristics, they are mostly used indoors. Therefore, the A standard light source is adopted for color measurement of samples based on indoor lighting conditions. The A light source is a carefully specified tungsten light source. Other light sources, such as fluorescent light sources, can be used in many types of applications. For example, some textile factories use fluorescent light sources. Therefore, a reasonable light source should be selected as the mutually recognized measurement method based on actual usage conditions and user requirements. Once agreed upon by both parties, color measurement must be conducted under the same conditions. This helps reduce unnecessary systematic errors and human errors, achieving the optimal consistency in color measurement. 

The 3nh high-precision spectrophotometric colorimeter adopts a combined LED light source with long lifespan and low power consumption, which includes UV (ultraviolet) and UV-excluded options. This design can meet the color difference detection needs of different users and supports the selection of multiple light source modes.

A powder coated surface is most commonly measured for thickness post curing using a digital coating thickness gauge. This method is non-destructive, helps verify coverage uniformity and meets quality control standards. A powder comb gauge is used to estimate thickness for a pre-cured coating.

Powder paint gloss levels are commonly classified as:

● Flat/Matte: 0–10 GU

● Satin: 10–40 GU

● Semi-Gloss: 40–70 GU

● Gloss: 70–85 GU

High Gloss: 85+ GU
These ranges can vary by manufacturer and application angle.

Common sources like D65, TL84, and CWF mimic daylight, store, home, and fluorescent lighting, and are used to provide conditions for dependable color comparison.

The color measurement theory is the quantification of the interaction of materials with light, either absorption, transmission, or reflection. It employs standard colour spaces (such as CIELAB) and devices (colorimeters, spectrophotometers) to code the visual colour into objective and reproducible data.

In the study of chemical reactions, calorimetry deals with changes in heat (energy and enthalpy). Spectrophotometry is the measurement of the light absorbance or light transmittance to determine the concentration or color of a solution. The first one monitors the thermal processes, whereas the second one addresses the aspects of light and color.