Measuring zinc coating thickness is most commonly using magnetic induction. The gauge measures how far the magnetic probes are to the metal base under the zinc. This is the most reliable way to measure the thickness and the preservation of the galvanization.

The principle of colorimetry is the law of Beer-Lambert, which says that the intensity of light absorbed by a colored solution is proportional to the concentration of the absorbing species and the path length. It measures the extent of light that is absorbed at certain wavelengths.

Use our 3nh company approved light. Replace all of the same type together and recalibrate to keep consistent color rendering. We usually do not recommend customers to modify it themselves, as this can affect the accuracy of the color and cause unnecessary losses

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

Gloss level is not given out in percentage but in gloss units (GU). In practice, however, 100 GU is considered 100 percent reflective. To contrast visually, the 20-40 GU is a low-gloss surface, and 85 or more is almost 100 percent mirror-like reflection.

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

For accurate results, install a clean and well temperature-regulated booth that is also sheltered from reflective surfaces and direct sunlight. Ambient light in the booth and the surrounding area from where the light is being viewed should not mix.

There are many factors that can influence accuracy such as surface roughness, temperature, substrate material, and calibration settings. For ferrous metals, external magnetic fields can also distort measurements. Proper calibration and preparation will help reduce the impact of these factors.

The measurement of color varies according to context in several units. Such common units are L*a*b* (CIELAB), RGB (Red-Green-Blue), and color difference (Delta E). In light absorption, there are no units assigned to absorbance. But the quantitative analysis of absorbance obeys Beer's Law in colorimetry.

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.