| 摘要 |
PURPOSE:To detect surely the state of flow of a magnetic fluid in a pipeline by detecting the presence of the flow of the magnetic fluid from the fluctuation of the magnetic field intensity caused by the ununiformity with the elapse of time of magnetic characteristics of the magnetic fluid in a channel. CONSTITUTION:The intensity of a magnetic field generated in a channel 1 by an exciting coil 4 fluctuates, since the density of a magnetic fluid in the channel 1 varies slightly and momentarily. An induced current corresponding to this change in the intensity of the magnetic field flows through a detecting coil 5. A signal 8 corresponding to the change in the density is extracted 7 from said induced current, and the stoppage of the flow of the magnetic fluid in the channel 1 is decided 9 according to the fall of the amplitude below a prescribed value. |
