Vacuum Brazed Aluminum Thermal Plate Inspection and Joint Quality Testing
Vacuum brazed aluminum plate acceptance demands 100 percent inline ultrasonic C-scan inspection and helium leak validation below 10-6 mbar L/s to prevent field coolant leaks.
Pressure Decay Testing
Meaning
Leak detection method that measures the drop in internal pressure of a sealed component over a fixed time interval. Many manufacturers use pressure decay testing to verify the air-tightness of battery enclosures and cooling circuits. This technique is faster and cleaner than underwater bubble tests and is easily integrated into automated production lines.
Measurement Cycle
Process begins by filling the part with compressed air and allowing the pressure to stabilize to account for adiabatic heating. During the actual pressure decay testing phase, a high-resolution sensor monitors the change in pressure with extreme precision. If the drop exceeds a pre-set limit, the system identifies the part as leaking and removes it from the line.
Temperature Sensitivity
Variations in the environment can mask a leak or cause a false failure because gas pressure is directly related to the temperature. Compensation for these changes is required during pressure decay testing to ensure that the results remain consistent throughout a production shift. Some systems use a reference volume to cancel out the effects of ambient temperature fluctuations.
Leak Rate
Conversion of the observed pressure drop into a volumetric flow rate allows for comparison against engineering standards. The sensitivity of pressure decay testing is sufficient for detecting small pinholes in cast aluminum housings or weld seams. This test is the primary gate for ensuring the long-term protection of the battery cells from moisture ingress.
Reliability of the seal is confirmed by the absence of a significant pressure drop during the evaluation period.