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

The accuracy of colors is determined by comparing the values of the colors (L*a*b*) of a sample with a standard reference sample using tools such as spectrophotometers. The variation is measured as ΔE. The smaller the value of ΔE, the more accurate, the nearer to the target color.

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.

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.

To take care of a haze meter to make it last longer, ensure that it is cleaned, recalibrated regularly, and stored in a dry, dust-free place. 

Powder paint gloss levels are classified as:

● Flat: 0–10 GU

● Satin: 11–40 GU

● Semi-gloss: 41–70 GU

● Gloss: 71–85 GU

● High Gloss: 86+ GU
 

These are measured at a 60° angle for standardization.

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.

True color in chemistry is the color seen in a solution or compound in standardized conditions. It depends on electronic transitions in molecules, specifically absorption of a particular wavelength of light, and this depends on the structure of the compound.

Color evaluation will change based on how a sample is viewed.  A 45° viewing angle to the source is recommended to reduce shading and achieve consistent comparison.

Zero calibration of a hazemeter is a critical pre-measurement procedure to ensure the instrument’s accuracy by resetting its baseline to "zero" when no haze or light attenuation is present.

1. Align the hazemeter’s measurement window with air or a black background, ensuring no objects block the window.

2. Press the hazemeter’s zero calibration button and wait for the instrument to complete automatic calibration. At this point, the instrument should display a zero haze value and a zero light transmittance value.

3. Observe the instrument’s display to confirm the zero calibration result stabilizes near zero. If the zero calibration is inaccurate, repeat the above steps multiple times until the displayed haze and light transmittance values stabilize near zero.

Perform 0-degree calibration before testing, this eliminates inherent instrument drift, environmental interference, or residual signal errors, ensuring subsequent measurements of transparent/translucent samples (e.g., plastic films，pvc, glass, coating, displays and cosmetic packaging) are reliable. Correct for minor instrument deviations caused by long-term use, temperature changes, or power fluctuations.