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Reverse Light Air Tightness Testing Solution

I. Importance of Airtightness Testing for Reverse Lights

Although small in size, the sealing performance of reverse lights is critical to overall vehicle safety and user experience. As a key component of the rear signal lighting system, reverse lights are typically located at the rear edge of the vehicle. If not properly sealed, the following issues may occur:

Problem Description
Short Circuit Due to Water Ingress Rainwater or car wash water seeps in, causing circuit short circuit and lighting failure.
Fog Reduces Lighting Efficiency Moist air enters and forms fog, reducing brightness and light penetration.
Corrosion Damage Moisture remains inside, causing corrosion of internal metal components and shortening service life.
Fails to Meet Safety Standards Poor sealing may result in failure to pass relevant safety certifications.
Reverse Light Structure Diagram Figure 1: Reverse Light Structure Diagram

Case Warning

In 2022, a domestic automotive lighting manufacturer supplying reverse lights for a Japanese brand faced quality complaints about water ingress during rainy days. Analysis revealed minor leakage at the hot-melt sealing edge after injection molding. Due to the small size of the light, traditional manual water testing failed to detect the issue. The customer urgently introduced a high-precision airtightness tester using the mass flow method for 100% airtightness testing of each assembly, effectively resolving the leakage problem and passing the client's audit.

II. Common Airtightness Testing Methods for Reverse Lights

Depending on the structure and precision requirements of the reverse light, the following airtightness testing methods can be selected:

Method No. Method Name Principle Advantages Applicable Scenarios
1 Differential Pressure Method Inject air and pressurize the lamp body; check if pressure drops Low cost, fast testing Small and geometrically simple reverse light assemblies
2 Mass Flow Method Uses a mass flow sensor to detect internal leakage rate High accuracy, stable, suitable for automation High precision or with LED control circuitry
3 Helium Leak Detection (Optional) Used in R&D or high-end vehicle models to detect micro leaks High cost, mainly for verification stages High-precision R&D or premium models
Reverse Light Airtightness Testing Equipment Figure 2: Reverse Light Airtightness Testing Equipment

III. Operating Steps for Airtightness Tester (Mass Flow Method Example)

Step No. Description
1 Place into Test Fixture: Insert reverse light into dedicated sealed fixture
2 Close Fixture: Fixture clamps and seals the light housing
3 Inflate & Pressurize: Use the tester to inflate the lamp to a set pressure (e.g., 50–150kPa)
4 Pressure Stabilization: Hold pressure for 2–3 seconds
5 Leakage Detection: Device measures leak flow in sccm (standard cubic centimeters per minute)
6 Pass/Fail Judgment: If leak is below threshold (e.g., 0.3 sccm), it's deemed qualified
7 Result Output: Supports MES integration for data traceability and batch management

IV. Conclusion

Airtightness testing for reverse lights is crucial to ensuring waterproofing, dustproofing, and reliable signaling. Introducing high-precision airtightness testers is a standard method for delivering high-quality lighting products.