AUF DER BASIS DER CORIOLIS-KRAFT ARBEITENDER MASSESTROEMUNGSMESSER

摘要

In a mass flowmeter of the Coriolis type the fluid to be metered is conducted through a pipe which is coiled to form a double loop 10,11. The pipe is anchored at its inlet and outlet ends and also at its center C which is the junction of the two loops to define a tuning fork in which the identical loops on either side of the anchored center function as tines that are free to vibrate as well as to twist. An electromagnetic driver 16 mounted at the vertex of the double loop is electrically energized to cause the loops to vibrate in phase opposition at the natural frequency of the tuning fork. The fluid passing through the double loop is subjected to Coriolis forces, thereby causing the vibrating loops 10,11 to torsionally oscillate in accordance with the mass flow of the fluid. Capacitance sensors 18,19 are symmetrically mounted on the respective loops to yield signals having a difference in magnitude and phase that depends on the amplitude of the torsional oscillations, these signals being applied to a differential amplifier 22 whose output is proportional to the mass flow of the fluid. <IMAGE>