| Title |
Development of a Non-contacting Capacitive Sensor Based on Thompson-Lampard Theorem for Measurement of μm-order Displacements |
| Authors |
김한준(Kim, Han-Jun) ; 강전홍(Kang, Jeon-Hong) ; 한상옥(Han, Sang-Ok) |
| Keywords |
Capacitive Sensor ; Capacitance ; Electrode ; Parallel Plate ; Guard |
| Abstract |
Non-contacting capacitive sensor based on Thompson-Lampard theorem have been fabricated and characterized for measuring of 때 order displacements. To overcome disadvantages of the existed capacitive sensors of parallel plate type with 2-electrodes and 3-electrodes, the developed new sensor was designed to have 4-electrodes with a constant gap of 0.2mm between the electrodes. Two of the electrodes were used as a high potential electrode and a low one, the other two electrodes were used as guard electrodes. These electrodes were made from copper using RF sputtering system on a sapphire plate with diameter 17 mm and thickness 0.7 mm. This sensor can be used for measuring the distance not only between the sensor and metallic target connected to ground potential but also non-metallic target without ground connection. |