| 摘要 |
PURPOSE:To effect cost-down by reducing exciting current and number of turns of coils, by arranging permanent magnets or exciting coils emitting vertically to the magnetic field of exciting coils magnetic fluxes oriented to the inside of pipe respectively in the neighborhood of a pair of electrodes located on the pipe wall. CONSTITUTION:Permanent magnets 11 emitting magnetic fluxes 12 vertically to magnetic field 3 of exciting coils 4 towards inside of a measuring pipe 2 are installed in the neighborhood of a pair of electrodes 6 on the outer side of the measuring pipe 2. As the magnetic fluxes of exciting coils 4 pass on the inside instead of outside of the measuring pipe 2 rejecting magnetic fluxes 12 emitted from the permanent magnets 11, the magnetic density inside the pipe is increased by the magnetic coils 4. Consequently, reduction of exciting current and number of turns of coil enables reduction of costs. |
