Coriolis type mass flowmeter utilizing phase shifters for phase shifting of the output signals

摘要

A Coriolis type mass flowmeter utilizing a measuring tube through which flows the fluid being examined and a pair of Coriolis signals generated thereby, wherein are provided a first and second A/D converter to convert the respective pair of Coriolis signals into respective digital signals; a first and second phase shifter for converting the respective digital signals to output signals each deviated from the respective digital signals by 90; a timing clock generator for supplying the first and second A/D converter with timing signals which are independent of vibrations of the Coriolis signals, and trigonometric calculating device for obtaining tan using the following equation: tan =(bc-ad)/(ac+bd), wherein a and c represent the outputs from the A/D converters, and b and d represent the outputs from the phase shifters, and tan represents the tangent signal of the phase difference between the pair of Coriolis signals, whereby the speed of calculation is considerably increased and error of calculation is substantially eliminated.