WAFU
Vehicle Monitoring Sensor Airtightness Testing Solution
1. Product Overview
These sensors are mostly installed outside the vehicle or near the vehicle body edges, exposed for long periods to complex environments such as rain, dust, high temperatures, condensation, and varying air pressures. Poor sealing may lead to:
| Issue | Description |
|---|---|
| Lens fogging, blurred images | Affects autonomous driving and assistive decision-making |
| Water ingress causing short circuit of internal electronic components | Module failure and system errors |
| Sensor false alarms or no response | Safety hazards exist |
| Failure to pass IP67/IP69K protection certification | Cannot be shipped or may be returned by customers |
Figure 1: Vehicle Monitoring Sensor Illustration
Case Study
In 2023, a well-known domestic Tier 1 supplier produced ADAS front-view camera modules for a European OEM. The customer required products to pass IP69K certification. Initially, some products experienced water ingress during high-pressure spray testing. By introducing airtightness testers (mass flow method) combined with automated sealing fixtures, 100% factory airtightness testing was achieved, ensuring each product’s airtightness ≤0.2 sccm, successfully passing EU standards and enabling mass production delivery.
2. Detailed Professional Testing Solution
Comparison of Testing Methods
| Method No. | Method Name | Principle | Applicable Scenario |
|---|---|---|---|
| 1 | Mass Flow Method | Real-time monitoring of gas flow rate to detect airtightness | High precision, suitable for small electronic sealed parts like cameras and radar modules; suitable for automated mass production line testing |
| 2 | Differential Pressure Method (Pressure Decay) | Measures pressure changes in chamber to determine leakage | Lower cost but slightly less precise than flow method; suitable for some simple-structure sensors with large internal volume |
| 3 | Helium Leak Detection (R&D use) | Detects extremely small leaks, suitable for early prototype verification | Higher cost and longer testing time; used for micro-leak localization analysis in development stage |
3. Typical Testing Process Demonstration
Taking the mass flow method as an example:
| Step No. | Specific Step |
|---|---|
| 1 | Product placement: Place the sensor (e.g., camera) into a sealed test fixture |
| 2 | Seal construction: Simulate the sensor's actual assembly sealing structure using the fixture |
| 3 | Inflation and pressurization: Set test pressure (commonly 50–200 kPa) to inject air into the sensor cavity |
| 4 | Pressure stabilization: Wait for system pressure to stabilize to avoid interference |
| 5 | Airtightness testing: Use the airtightness tester to read leak flow rate (e.g., ≤0.2 sccm) |
| 6 | Automatic judgment: Automatically determine pass/fail according to preset limits |
| 7 | Data recording: Test data is uploaded in real-time to the MES system for full process traceability |
4. Conclusion
Airtightness testing of engine cover assemblies is a critical process to improve the vehicle’s protection level, heat insulation, sound insulation performance, and user experience, and is a key link in the "functional guarantee" of automotive exterior structural parts.