Abstract: A method of generating reference pressures by a pressure generator, which generates a reference pressure according to a mass applied to an end face of a piston using a mobile data processor including the steps of: selecting the standard instrument out of a plurality of standard instruments which are measured as regards characteristic properties and the characteristic properties of which are stored in the form of reference data at a central storage location; connecting the mobile data processor to the central storage location and automatically downloading the reference data of the selected standard instrument and storing the same in the mobile data processor; and for processing the reference data, each applied mass and the local environmental data in the measuring environment into the pressure values assigned to the masses applied in each case as the reference pressures of the standard instrument.