| 摘要 |
PURPOSE:To obtain the flowmeter having an excellent S/N ratio, by arranging two sensors at two points, where the ratio of the noise component due to the vibration of a force receiving body is substantially equal to the noise component due to the strain of a pipe, performing signal conversion, and thereafter performing computation. CONSTITUTION:In a detector 10 of the vortex flowmeter, a tubular nozzle 12 is provided at a right angle with the pipe 11 wherein fluid to be measured flows. The pillar shaped force receiving body 13 is inserted at a right angle with the pipe passage 11 through the nozzle 12. The first piezoelectric sensor 14a and the second piezoelectric sensor 14b are compressed and fixed to the inside of a concave part 13 of the force receiving body 13 with a specified interval being provided. Electric charges q1 and q2 are detected by the piezoelectric sensors 14a and 14b. The noise electric charge due to the vibration of the force receiving body 13 and the noise electric charge due to the strain of the pipe are superimposed on the signal electric charges obtained from the lift of the vortex in the q1 and q2, respectively. They are computed in an operator through an operation amplifier. |
