The pressure conditions in the pressure cylinder are changed with the aid of a diaphragm compressor, which can also act as a vacuum pump. In this way the test gas can be subjected to over as well as to underpressure conditions. With the model 400 Apparatus a convincing experimental proof of the Boyle-Mariotte law can be demonstrated easily. The high precision of the data acquired as well as the important visualization in the test ensure good comprehensive.
