| 摘要 |
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 r, sigma t 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.
|
