The CETATEST 925 test device is suitable for flow testing using compressed air as test medium. The measuring method uses the fact that in a laminar flow, the pressure difference between two measuring points is directly proportional to the volume flow. Laminar flow elements (LFE) are used to laminarise the air flow. The pressure difference is measured with a differential pressure sensor. In the direct method, the air flow supplied by the pressure regulator first flows through the LFE and then through the test part. In the indirect method, the LFE is located in the outlet flow of the test part. The use of an electronic pressure regulator and flow calibrations at different LFE pressures results in an extended range of applications.