measuring, controlling, regulating, signaling, checking and recording and computer programs for use in connection with such apparatus for use principally in the field of physics, electrical, electronic, electromagnetic, electromechanical, optical, acoustic, particle radiation, ultrasound, hydrostatic and mechanical apparatus for measuring, controlling, regulating and checking, in particular for determining and monitoring the filling level of containers and for determining and monitoring of pressures, in particular process pressures, as well as computer programs; computer programs for use in connection with such apparatus capacitive, hydrostatic, pulse echo, optical light and laser, electromechanical, particle radiation, vibration, conductivity and microwave apparatus for measuring a given filling level, as well as associated evaluation, display and protection apparatus, and parts of such apparatus; ceramic and metallic pressure pickup cells, pressure sensors and pressure transducers in combination with pressure sensors; computer programs for operating said apparatus