Automotive and EV Battery
Click to Enlarge
- E-mobility and EV Battery Assemblies
- Engine blocks, cylinder heads, oil pan, turbo and intake.
- Exhaust and emission systems.
- EGR coolers.
- Sensors and switches
- Water pumps and associated housings.
- Machined aluminum die cast components.
- Fuel components & delivery systems, fuel tanks, floats, lines.
- Brake calipers, boosters and fluid reservoirs.
- Transmissions, front & rear differentials & steering systems.
- Heating & cooling systems, heater cores, radiators.
- Exterior lighting, headlights, taillights, marker lights.
- Hybrid battery cases & components.
The “Top 3” leak testing methods used in automotive manufacturing are
Pressure or Vacuum Decay, Differential Pressure, and Mass Flow. These leak testing technologies are used in over 90% of Automotive applications worldwide.
Standard Pressure Decay or Vacuum Decay is a method typically used to detect leaks in the 1-1,000 sccm leak rate range and works excellent for products such as engine assemblies, transmissions, sensors, and machined die-castings.
Pressure or vacuum decay is a simple test with good resolution over a wide pressure range. With this procedure the part is filled or evacuated to test pressure, stabilized and tested for a specific duration. Once in the test step, the tester monitors and records the pressure or vacuum loss. Any pressure or vacuum loss indicates a leak. The final test result is compared to user-defined leak or flow limits to pass or fail the part.
Differential Pressure Decay is typically used to detect smaller leak rates in the 0.1 sccm to 100 sccm leak rate range and is the preferred method for fuel tanks and fuel injection systems, EGR coolers and brake calipers. When the leak rate is too low for standard pressure decay, Differential pressure decay is the option.
Differential Pressure is a relatively simple test with excellent resolution. With this procedure the test part and a master reservoir are filled to test pressure, stabilized and tested for a specific duration. Once the part is filled and stable, the difference in pressure between a master reservoir and a production part is compared to determine the leak rate. The full scale of the DP transducer is much smaller, providing higher pressure loss resolution than standard Pressure Decay or Mass Flow to measure smaller amounts of decay.
Mass Flow Testing is a method typically used to detect leaks as small as 2 sccm to as large as 300 LPM. Mass Flow is the preferred testing method for parts that are elastic (stretch and grow when pressurized), parts that may vary in volume (in3), parts that have very large volume, or parts that have high reject leak rates. Prime parts to test include exhaust or emission systems, automotive lighting, and plastic fluid reservoirs.
Similar to pressure decay, with mass flow the part is filled to test pressure, stabilized and tested for a specific duration. Rather than measuring the pressure decay during the test step, a high-speed mass flow sensor is introduced to measure the amount of “replacement” air mass required to maintain the setpoint /target pressure. As an example, If 100 cc (cubic centimeters) of air volume needs to flow into the test component per minute to maintain a specific pressure, the leak rate is 100 cc per minute. During initial setup, the flow characteristics of a master part are memorized. Production parts are then compared to the master part parameters to determine if they pass or fail.
Standard Pressure Decay or Vacuum Decay is a method typically used to detect leaks in the 1-1,000 sccm leak rate range and works excellent for products such as engine assemblies, transmissions, sensors, and machined die-castings.
Pressure or vacuum decay is a simple test with good resolution over a wide pressure range. With this procedure the part is filled or evacuated to test pressure, stabilized and tested for a specific duration. Once in the test step, the tester monitors and records the pressure or vacuum loss. Any pressure or vacuum loss indicates a leak. The final test result is compared to user-defined leak or flow limits to pass or fail the part.
Differential Pressure Decay is typically used to detect smaller leak rates in the 0.1 sccm to 100 sccm leak rate range and is the preferred method for fuel tanks and fuel injection systems, EGR coolers and brake calipers. When the leak rate is too low for standard pressure decay, Differential pressure decay is the option.
Differential Pressure is a relatively simple test with excellent resolution. With this procedure the test part and a master reservoir are filled to test pressure, stabilized and tested for a specific duration. Once the part is filled and stable, the difference in pressure between a master reservoir and a production part is compared to determine the leak rate. The full scale of the DP transducer is much smaller, providing higher pressure loss resolution than standard Pressure Decay or Mass Flow to measure smaller amounts of decay.
Mass Flow Testing is a method typically used to detect leaks as small as 2 sccm to as large as 300 LPM. Mass Flow is the preferred testing method for parts that are elastic (stretch and grow when pressurized), parts that may vary in volume (in3), parts that have very large volume, or parts that have high reject leak rates. Prime parts to test include exhaust or emission systems, automotive lighting, and plastic fluid reservoirs.
Similar to pressure decay, with mass flow the part is filled to test pressure, stabilized and tested for a specific duration. Rather than measuring the pressure decay during the test step, a high-speed mass flow sensor is introduced to measure the amount of “replacement” air mass required to maintain the setpoint /target pressure. As an example, If 100 cc (cubic centimeters) of air volume needs to flow into the test component per minute to maintain a specific pressure, the leak rate is 100 cc per minute. During initial setup, the flow characteristics of a master part are memorized. Production parts are then compared to the master part parameters to determine if they pass or fail.
Leak Test Sequence
A typical air leak test sequence consists of 3 primary steps, fill, stabilize & test. Leak test cycle time is based on how fast you can reach the desired target positive or vacuum pressure. Once pressure becomes stable, measuring the least amount of decay possible to provide a repeatable test result.- Fill - During the fill step, the part being tested is pressurized or evacuated to a specified level.
- Stabilize - During the stabilize step the part is allowed to stretch/expand or contract (based on the test applied) and cool until stable.
- Test - During the test step the pressure, vacuum or flow level is monitored, and the product is either passed or failed at the end of the test step based on pre-set leak or flow limits.