Usually you will find haze and transmittance standards of ASTM D1003, ISO 13468, & JIS K7105.

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.

Take L*a*b* readings of two samples using a colorimeter or spectrophotometer and calculate color difference using the 3 formula (Delta E). The difference in 0 is the reported Delta-E, which shows how visible the change is, whereas the thresholds define the acceptability as per the application requirements.

Who are we? Threenh Technology: 22-Year Professional Color Measurement Solution Provider

Threenh Technology is a Chinese professional Measurement Instrument manufacturer with 22 years of industry experience, specializing in the field of color measurement and surface gloss detection. Integrating research and development, design, production, marketing, and sales, the company takes technological innovation as its core and is committed to providing global customers with high-precision and intelligent testing instruments as well as professional solutions.

A digital coating thickness gauge is used to measure the thickness of dried paint. It measures coating thickness specification non-destructively, helping to maintain consistent quality and performance.

To quantify color change, take the original L*a*b* values of a sample, and reread after exposure or processing. Compute the difference as 1/2(Emut1 Emut2). The larger the value of ΔE, the more obvious the change of color is, which can be used in quality or stability testing.

A colorimeter or spectrophotometer should be used to measure the color of a solution. The instrument directs light through the liquid and quantifies absorbance at certain wavelengths. The values obtained indicate the color intensity of the solution and, by default, the concentration of the solution.

The color measurement test applies a colorimeter or spectrophotometer to evaluate the way a sample reflects or absorbs light. It is given in objective color values (L*a*b*, RGB, or absorbance) and is usually contrasted to a standard in quality control or compliance.

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.

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.