FLOW RATE MEASURING DEVICE

PROBLEM TO BE SOLVED: To attain a flow rate measuring device capable of avoiding erroneous flow rate measurement by detecting, when the flow rate measuring device is under a magnetic influence, its state.SOLUTION: A flow rate measurement device includes: at least a pair of oscillators 1, 2 which are provided in a fluid pipeline 3 to transmit/receive ultrasonic signals; a transmission part 4 which drives the oscillators; and a reception part 5 which performs reception from the oscillators, and is constituted by further being provided with a magnetic force detection part 7 capable of detecting magnetic force. Thus, when a magnet, etc. approaches the flow rate measuring device, the magnetic force detection part 7 detects magnetic force of the magnet, etc. to recognize that the flow rate measuring device is influenced by the magnetic force, and discontinues the measurement to block the magnetic force according to the state to eliminate an adverse effect to measurement due to the magnetic force.