D65, TL84, A light, CWF, and UV are the most common standardized sources used for precise color matching.

 Color is measured using devices such as colorimeters, spectrophotometers, and spectroradiometers. Colorimeters are easier and good for simple color quality tests. Whereas spectrophotometers yield detailed spectral information. Hence, suitable for laboratories and industries.

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.

The color may be quantified in L*a*b* (CIELAB units), RGB values, CMYK (printing), and ΔE (color difference). Colorimetric assessment measures also apply spectral reflectance and absorbance (A), particularly in liquids and solutions.

Keep light booths clean, maintain the light source lamps, readjust the calibrated light source, and ensure that dust and fingerprints do not settle on the viewing area.

To operate the haze meter, first calibrate the instrument, clean the sample, position it correctly in the holder, and initiate the measurement. The instrument then shows the haze and overall transmittance readings.

To keep the light box calibrated and to ensure accurate and steady lighting, clean the inside, replace the lamps when needed, check the calibration and record the hours use

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.

The Colour Assessment Cabinet (CAC) is a controlled environment used for the visual evaluation of color wherein the light sources are consistent.

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.