초록 ▼

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 t

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 sr, st in the tube cross section. The output signals sr, st 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. The invention makes possible the exact measurement of the pressure inside a tubular body without contact with the pressure medium, and excludes disturbing influences as may arise due to temperature gradients, longitudinal stresses and the like.

대표청구항 ▼

A device for measuring the pressure in a tubular body, comprising at least one pair of electromechanical transducer means arranged at one position at least along the longitudinal axis of the tubular body, for detecting the mechanical stresses set up in the radial and tangential directions by the pre

A device for measuring the pressure in a tubular body, comprising at least one pair of electromechanical transducer means arranged at one position at least along the longitudinal axis of the tubular body, for detecting the mechanical stresses set up in the radial and tangential directions by the pressure and for generating analog output signals for the radial and tangential stresses, and signal processing means receiving the output signals from the transducer means for generating a measuring signal proportional to the difference between the inside and outside pressures, which can be fed to a signal evaluation means for further evaluation.