The differential pressure method In this case, the pressure drop or pressure rise is measured with a differential pressure sensor (high resolution)
The Relative Pressure Method In this case, the pressure drop or pressure increase is measured with a relative pressure sensor (low Resolution)
The mass flow overflow method In this case, the test part is filled very quickly from a buffer volume and then the downstream air stream is measured with a mass flow sensor.
The mass flow post-flow method The test part and the buffer volume are simultaneously filled with the nominal test pressure. Subsequently, the downstream air stream is measured with a mass flow sensor. Pressure ranges from vacuum to max. 1000 kPa with the highest resolution possible