| Автор | J C S Richards |
| Дата выпуска | 1976-08-01 |
| dc.description | The design of an instrument employing a capacitive transducer for non-contacting measurements of displacement and vibration is considered, with the aim of combining high resolution and linear response over a wide range. The three-terminal transducer in which movement of the earthed workpiece alters the capacitance between two non-earthed electrodes, is preferred to the two-terminal transducer, in which a capacitance to earth is measured. A two-dimensional theoretical analysis leads to practical design formulae and methods of construction are discussed in detail. A typical transducer 12 mm in diameter can give a sensitivity constant to within 3% and a maximum error of 3 mu m over a range of 500 mu m, or 1% and 1 mu m over 250 mu m; the resolution is determined either by electrical noise at 1 nm for a bandwidth of 1 Hz, or by ambient changes at <50 nm for 1 degrees C change in temperature; vibrations of frequency <10kHz can be observed; performance with typical non-planar workpieces is quoted, and the possibility of measuring displacements of dielectrics is indicated. Transducers with a logarithmic response are described. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Linear capacitance provimity gauges with high resolution |
| Тип | paper |
| DOI | 10.1088/0022-3735/9/8/013 |
| Print ISSN | 0022-3735 |
| Журнал | Journal of Physics E: Scientific Instruments |
| Том | 9 |
| Первая страница | 639 |
| Последняя страница | 646 |
| Аффилиация | J C S Richards; Dept. of Natural Philosophy , Aberdeen Univ., Aberdeen, UK |
| Выпуск | 8 |
