Pressure Decay Testing VS Differential Pressure Testing

Pressure Decay Testing

Pressure Decay Testing：pressure decay testing is a detection method to judge the leakage by directly measuring the reduced pressure of the test object through the pressure sensor.

 Operation Process: firstly fill the test air or pressure and seal it, and then use a pressure sensor (pressure gauge) to measure the pressure reduction，finally directly obtain the leakage of the tested part.

 Test Cycle: fill, balance, test and exhaust.

Differential Pressure Testing

Differential Pressure Testing: the differential pressure method is to fill the same pressure into the tested part and the standard part, and then use the differential pressure sensor to read out the difference of pressure, so as to identify the leakage of the tested part.Operation Process: firstly open the valve and fill the standard part and the tested part with the same air or pressure, and the pressure at both ends of the differential pressure sensor is the same. Then close the valve, the pressure on the standard side of the differential pressure sensor is constant, and the pressure on the tested side decreases if there is leakage of the tested part. The differential pressure sensor compares the pressure at both ends to identify the leakage.

Test cycle: fill, balance, test and exhaust.

Pressure Decay Testing VS Differential Pressure Testing

1. Pressure Decay Testing: large measuring range and low precision, which is suitable for testing the large leakage of products.

   Differential Pressure Testing: small measuring range and high precision, up to 0.1Pa. Suitable for testing small leakage of products.

2. Pressure Decay Testing: lower stability because it is greatly affected by like temperature and some other conditions.

   Differential Pressure Testing: higher stability because the standard part port and the test port are connected to the standard part and the tested part     respectively, the pressure fluctuation error caused by the temperature of the product is offset to a certain extent, and the stability of the test results     is improved.

3. Pressure Decay Testing: long test time.

Differential Pressure Testing: short test time.