Patent ID: 7938022

Claim:
A flowmeter comprising: a fluid pipe forming a flow path for allowing a measurement fluid to flow therethrough and having electric conductivity; an oscillator constituted with a magnetic substance and a coil corresponding to the magnetic substance, where one of the magnetic substance and the coil is fixed to the fluid pipe to oscillate the fluid pipe; an oscillation circuit receiving supply of electric power in a non-insulated manner from an external power source and supplying the electric power to the coil in a non-insulated manner so as to drive the magnetic substance; a plurality of detectors that are disposed to be spaced apart from each other along the flow path of the fluid pipe to detect a state of vibration of the fluid pipe; a calculator that calculates a mass flow rate of the measurement fluid that passes through the flow path of the fluid pipe based on each vibration that is detected by the plurality of detectors; an insulating unit for insulating the coil from the magnetic substance and/or the electrically conductive fluid pipe; and a shielding unit being short-circuited to have a stable electric potential relative to the external power source and shielding the coil against the magnetic substance and the fluid pipe.