Method and apparatus for stabilizing parasitic error capacitance in oil quality sensors

摘要

A sensor for detecting changes in the dielectric constant of a liquid is described. The sensor has two electrodes immersed in the liquid with dielectric surfaces substantially parallel with each other, and a ramp disposed on a support between the electrodes. The ramp intersects the surfaces at obtuse and acute angles respectively and provides a surface disposed at an angle relative to an electric field extending between the two electrodes, thereby reducing parasitic effects of the sensed dielectric content of the liquid. Slots in the electrode adjacent the lower end of the ramp reduce the strength of the field proximate to the ramp and thereby further reduce the parasitic effects.