It is a core component that integrates structural strength, sealing performance, and human-machine interaction features. It comprises several sub-assemblies, including the door body panel, interior trim, glass-lifting system, door-lock mechanism, and sealing strips. The quality of the car door directly impacts vehicle safety (collision protection), sealing effectiveness (waterproofing and sound insulation), and ease of use (smooth operation of opening and closing).

Applicable scenarios 
Factory inspection of components: During mass production of car door assemblies, first-article inspection is conducted to verify dimensions, ensure proper assembly fit, and confirm functional compliance. Additionally, batch sampling inspections—covering 10%–15% of each production run—are performed to identify and reject nonconforming parts, such as deformed sheet metal, misaligned holes, or improperly fitted functional components. This rigorous process ensures that the car doors delivered to automakers meet quality standards and helps minimize the rate of incoming material rejections. 

Automotive manufacturers' incoming materials and final assembly inspection: When automakers receive car doors, they use inspection tools to quickly verify critical parameters—such as hinge hole positions and sealing performance—to identify and address any deformation caused by transportation pressure. During the final assembly stage, pre-installation checks are conducted to fine-tune the alignment of the doors with the vehicle body, preventing costly rework (like readjusting hinges) due to uneven gaps—and ultimately helping to reduce overall assembly costs. 

R&D Phase Validation: During new vehicle development, it’s essential to evaluate the structural soundness of door prototypes (e.g., the layout of the anti-collision beam), their functional reliability (such as the lifespan of the lift mechanism), and the convenience of human-machine interaction (including aspects like door-opening force and the positioning of the grab handle). These assessments help refine and optimize the door design—for instance, by testing the noise-insulation performance of various sealing material options to identify the most suitable material solution.

Value Representation: Using this inspection tool, the rate of defective car doors can be kept below 0.05%, significantly reducing after-sales complaints caused by door quality issues—such as leaks, malfunctioning opening/closing mechanisms, and poor sound insulation, which currently account for 20%-25% of all vehicle-related after-sales complaints. At the same time, the tool boosts inspection efficiency while cutting down on quality control costs (a single unit can replace 6 to 8 manual inspectors). This helps automakers ensure the safety, sealing performance, and reliability of car doors, ultimately enhancing overall vehicle quality, boosting customer satisfaction, and strengthening their competitive edge in the market.