Abstract: A force transducer with an electromechanical transducer element for fitting in force plates (i.e. measuring platforms) includes adjacent a first axial end a radial mounting flange with a greater outside diameter than that adjacent the second axial end. This make it possible, after connecting the signal lines, to insert the transducer in a mounting hole of the base plate of the force plate and then fix it by welding, brazing, soldering or cementing. The transducer with its signal lines thus becomes an integral part of the base plate and is sealed completely against outside influences. The recesses of the base plate may be filled with a curable resin, providing further portection against mechanical shocks and corrosion influences while at the same time enhancing the rigidity of the force plate.

Abstract: A method and a device for measuring the pressure in a tubular body, for example, in the nozzle of a plastics injection molding machine, in the injection pumps of diesel engines, in gun barrels and the like, makes use of electromechanical transducers of piezoelectric, piezoresistive or strain gauge type to detect the radial and tangential mechanical stresses .sigma..sub.r, .sigma..sub.t in the tube cross section. The output signals s.sub.r, s.sub.t of the transducers are fed to a signal processing facility consisting of a subtraction circuit (for transducers of like polarity) or an addition circuit (for transducers of unlike polarity). The output signal of the signal processing facility is proportional to the difference between the pressures inside and outside the tubular body and may be fed to a further evaluation facility, such as a pressure display or process control device.

Abstract: A charge amplifier circuit includes an operational amplifier with an integrating capacitor between its inverting input and its output, and a resetting device with a switch that is closed during the reset phase for discharging the integrating capacitor. Provided at the output of the charge amplifier circuit is a circuit arrangement with a correction amplifier which when the switch is closed, automatically delivers a correction charge to the integrating capacitor, compensating the zero shift of the output voltage from the charge amplifier circuit during the measuring phase. This circuit arrangement is particularly suited for charge amplifiers with an extremely high ohmic input stage.