A differential pressure decay/leak standard leak test uses traditional dP pressure decay theories to test for a leak by measuring a differential pressure between a reference volume and the test piece calibrated to a standard volumetric flow. This test uses a differential pressure transducer to measure pressure loss correlated to a flow rate in scc/m.
Cincinnati Test Systems provides high precision differential pressure decay leak test systems. The LPC 528 is designed for reliable and accurate pressure decay leak detection.
Differential Pressure Decay Leak Standard Calibration Cycle
- A non-leaking master part is tested to establish the “zero leak” setpoint (master part loss)
- The master part is tested with the leak standard included in the test circuit to determine the maximum acceptable leak rate (master plus leak loss)
Using these setpoints, the leak test system establishes the “target flow window” for differential pressure decay leak detection.
The test cycle fills a test part and an equally sized reference tank to a specified test pressure, the air source is cut off, test pressure stabilizes, and a reference air isolation valve is closed. The differential pressure transducer measures the pressure on both sides of the transducer throughout the test period. At the conclusion of the test, the instrument calculates the differential pressure decay in flow units (sccm). If the flow rate is within the “target pressure window,” the part passes the leak test. If outside the target limits, the part fails the leak test and is rejected. See diagram below.