What are the applications of colorimeters in the automotive industry

Source：m.uninorths.com.cn Release date： 2025-06-25

The application of colorimeters in the automotive industry covers the entire process from component production to vehicle quality inspection. Its core function is to achieve correct color control by quantifying color parameters (such as CIE Lab values, Δ E, etc.), ensuring consistency in appearance and brand visual standards. The following are specific application scenarios and technical details:
1、 Automotive Painting and Paint Quality Control
1. Original paint color matching and mass production
Color grading stage:
When developing a new car, engineers measure the spectral reflectance of the target color palette using a colorimeter, generate Lab values (such as L *=45.2, a *=12.7, b *=8.3), and match them with the paint supplier's pigment database to calculate the pigment ratio. For example, Porsche's "Miami Blue" paint requires correct control of the ratio of blue pigment to pearl powder, with Δ E ≤ 0.5 to ensure color accuracy.
Mass production monitoring:
The paint surface of each car on the spraying line needs to be tested in real time by a colorimeter, and common testing points include parts that are easily affected by spraying angles such as car doors and engine hoods. If the Δ E of a certain car is greater than 1.5 (visible threshold to the naked eye), the system will automatically mark and trigger the rework process.
2. Paint repair and after-sales maintenance
The 4S store uses a colorimeter to scan the original paint color of the damaged area, generates color code data, and transmits it to the paint adjustment system to ensure that the touch up paint is consistent with the original car color. For example, BMW's "Esto Blue" metallic paint contains multiple layers of mica particles and needs to be tested at angles such as 60 °, 20 °, and 45 ° using a multi angle colorimeter (such as 3NH NR170) to avoid color differences caused by differences in light reflection.
2、 Consistency management of interior color
1. Plastic components (dashboard, door panels, etc.)
During the plastic injection molding process, changes in raw material temperature and mold pressure can lead to color deviation. The colorimeter can detect whether the brightness (L *) and saturation (C *) of the components meet the standards:
Case: The center control panel of Tesla Model 3 is made of matte black plastic, requiring the L value fluctuation of each batch of components to be ≤ 1.0, and the a and b * values to be ≤ 0.5, in order to avoid visual differences of "different shades" inside the same car.
2. Leather and fabric materials
When dyeing leather, a colorimeter is used to monitor the dye concentration and temperature, ensuring uniform color distribution in areas such as seats and steering wheels. For example, the Nappa leather seats of the Mercedes Benz S-Class must meet the requirement of Δ E ≤ 1.0, and the color deviation of different seats on the same car must be ≤ 0.8.
3、 Quality control of component suppliers
1. Exterior components (bumper, headlights, wheels, etc.)
Suppliers need to submit color palettes according to the standards of the host factory, and only after passing the color difference test can mass production be carried out. For example, Audi's matrix LED headlight cover needs to meet both transmittance and color coordinates (x, y) standards, and Δ E needs to be ≤ 0.8 to avoid light color deviation.
2. Chrome plated parts and decorative strips
The glossiness (60 ° glossiness ≥ 85GU) and color (bluish or yellowish) of the chrome plating layer need to be tested with a colorimeter in conjunction with a glossiness meter. BMW's "Hodgson Corner" chrome trim requires a b * value between -2.0 and 0.5 to avoid the phenomenon of "graying".
4、 Testing of special materials for new energy vehicles
1. Battery casing and heat dissipation components
The battery casing of new energy vehicles often uses anodized aluminum alloy, and the colorimeter needs to detect the color uniformity of the oxide film (such as Tesla battery casing requirements L *=75 ± 2, a *=± 0.5, b *=± 1.0), while ensuring that the thickness of the oxide film is positively correlated with the color (the darker the color, the more uniform the film thickness).
2. Intelligent surface (touch panel, ambient light)
Touch panels with backlighting need to detect color consistency under transparent conditions. For example, BYD's rotatable Pad frame requires Lab value fluctuations of ≤ 0.5 in white light mode to avoid color differences caused by uneven backlighting.
5、 Color Trend Research and Development
1. Development of new colors
Car manufacturers use colorimeters to analyze popular color trends (such as Pantone's annual color) and develop new colors based on material characteristics (such as matte, metallic, and pearl). For example, the "Stardust Purple" pearl paint launched by Mercedes Benz in 2024 requires a colorimeter to ensure that the Δ E under different lighting conditions is ≤ 0.3, presenting a "color changing" effect.
2. Standardization of enterprise colors
The iconic colors of enterprises (such as Ferrari Red and Jaguar Green) need to establish a strict color difference standard library, and global factories should uniformly use the same model of colorimeter (such as Aiseli CI64) for testing to ensure that the colors of different origin models are consistent.
6、 Upgrading detection equipment and technology
1. Portable VS desktop colorimeter
Portable instruments for production line inspection (such as Konica Minolta CM-26DG), supporting multi angle measurement (25 °, 45 °, 75 °), suitable for rapid on-site inspection; Desktop laboratory instruments such as Datacolor 650 have higher accuracy and can analyze spectral data.
2. Automated detection system
Car companies (such as Porsche and BMW) deploy online color difference detection robots on their final assembly lines, which use robotic arms equipped with color difference meters to scan the entire vehicle 360 °. The data is uploaded to the MES system in real-time and automatically alarms in case of abnormalities.

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