after the coriolisprinzip massendurchfluss working device.

摘要

This mass flowmeter is designed to be installed in pipelines having nominal diameters greater than about 150 mm. It has a support tube (11), a vibrating system (12) disposed axially in the support tube and consisting of two straight measuring tubes (21, 22) mounted in a holder (23, 15) at each of their ends, and a vibration exciter (50) which sets each measuring tube into natural-resonance flexural vibration at the center. The soft-magnetic armature (51) of the vibration exciter (50) is secured to one of the measuring tubes, and its electromagnet (52) is mounted in the wall of the support tube (11) opposite the armature (51) via the metallic, nonferromagnetic coil can (53) and contains a soft-magnetic core (54). The central portion (55) of the latter, which is disposed in an energizing coil (57), carries a permanentmagnet inset (58) at the end opposite the armature, and the edge portions (56) of the core (54) extend along the outside of the energizing coil. Vibration sensors ( 30, 31) for sensing the mechanical vibrations are mounted on both sides of and at preferably equal distances from the vibration exciter (50), and an evaluation circuit (60) is provided for determining the mass rate of flow from the phase difference of the signals delivered by the vibration sensors. This results in a very high efficiency and a linear excitation-current dependence of the vibration exciter.