FLOWMETER

PURPOSE:To provide a flowmeter which allows an ultrasonic transceiver to be rigidly fixed to a pipe conduit without changing a material of the pipe conduit, removes influences of ultrasonic components propagated in the pipe conduit and improves a measuring accuracy. CONSTITUTION:An ultrasonic vibration sensor 10 for receiving ultrasonic waves propagated from an ultrasonic transmitter 4 via a pipe conduit 1 is set outside a propagating route 9 of the pipe conduit 1 where ultrasonic waves in a fluid are propagated. A subtracter 11 is interposed between an ultrasonic receiver 5 and a demodulator 7 to subtract an output signal of the vibration sensor 10 from a synthesized signal B of the ultrasonic receiver 5. The subtracter 11 subtracts the output signal from the synthesized signal and outputs a signal corresponding to ultrasonic waves of the fluid passing tone route 9 to the demodulator 7. In consequence, since influences of the ultrasonic waves propagated in the pipe conduit 1 and received by the ultrasonic receiver 5 are eliminated, a measuring accuracy is improved. It is not necessary to change a material for the pipe conduit 1. Corrosion resistances of the pipe conduit 1 are kept favorably and manufacturing costs can be restricted to be small.