| 摘要 |
PURPOSE:To obtain the physical quantity transducer such as a highly accurate, electrostatic capacity type pressur difference transducer by holding a cylindrical detecting part and a magnet ring in floating state in a core by a magnetic force. CONSTITUTION:External pressure is guided to two pressure chambers 13 through an insulating fluid sealed in the inside, and acts on a magnetic fluid 18. As a result, a cell assembly 17 is displayed in the axial direction against the pressure P2 by a force f1 corresponding to the pressure difference DELTAP=P1-P2. Therefore the magnetic fluid 18 gives a force f2 to the cell assembly 7 in the direction against the force f1 of the pressure difference DELTAP. Then the cell assembly is stopped at the position where the forces f1 and f2 are balanced. The pressure difference DELTAP=P1-P2 simultaneously acts on a detecting diaphragm and deflects it to the low pressure side (P2 side). Then the electrostatic capacity between a pair of electrodes 2 and the detecting diaphragm 15 is changed. By measuring the change in said electrostatic capacity through a lead wire 20, the given pressure differene DELTAP=P1-P2 can be found. |
