Capacitive proximity monitoring device for corrosive atmosphere environment, e.g. for semiconductor wafer mfr

摘要

The capacitive proximity monitoring device comprises a capacitance field element or sensing element disposed in a corrosive atmosphere environment and being made of conductive plastic resistant for such an environment. Such conductive plastic is rendered conductive by carbon filling the plastic, or by adding iron particles to the plastic. The field element may be a functional part of a functional device that performs a function with respect to the presence of the liquid being sensed; and in some cases the field element is nonfunctional with respect to the liquid, but functional and sensing the capacitance and determining the presence or absence of liquid. The functional device may incorporate a valve or coupling for tubing.