Electromagnetic flow meter for measuring non-Newtonian fluids

摘要

The flowmeter has a measuring tube (11) of insulating material e.g. alumina, ceramic or hard rubber, through which the fluid flows. The tube is positioned between two diametrically opposed coils (12,13) in series. The induced voltage is picked up by electrodes (14,15) directed along radii (14-1,15-1) at opposite angles ( ) of 45 deg. or 60 deg. to the lines of flux (B). The magnetising current (i) from a generator (21) is reversible through one coil (13) by means of a switch (22) operated by a pulse width and frequency controller (23). An electronic evaluation circuit (24) produces a mean velocity signal (SV) and an index signal (SN) according to the setting of the reversing switch.