| 摘要 |
A capacitive fluid level sensor 10 comprising an electrically insulating support 12 which carries at least two elongate subtending electrodes 16, 18 which are spaced apart from one another uniformly along their lengths. Measurement electrical circuitry 30 is connected to the said at least two elongate curved electrodes 16, 18 to provide a measure which is indicative of the level of liquid into which the support is immersed when the sensor is in use. The electrically insulative support 12 is in the form of a rod 12, and the said at least two elongate electrodes 16, 18 extend longitudinally along the surface of the rod 12 or may be in the rod 12 adjacent the surface. The rod 12 may have a uniform, hollow or solid, circular cross section along its length, being 2cm 3m, with diameter 5mm - 20cm. The electrodes 16, 18 may adhere into recesses so that they are flush with the detector surface. Probe 10 may have a non-stick insulating coating 26 of Teflon (RTM) or PTFE. The electronics 30 may use resonant circuitry, constant current sources, step voltages or predetermined threshold values. |
