Abstract: A method of detecting the presence of a hazardous foreign voltage on a conductor includes the steps of sensing an electric field in the vicinity of the conductor with a first non-contact conductive sensor and sensing the electric field in the vicinity of the conductor with a second non-contact conductive sensor spaced a predetermined distance from the first non-contact conductive sensor. The difference between the electric field sensed by the first conductive sensor and the electric field sensed by the second conductive sensor is determined. The first conductive sensor preferably is shaped as a truncated spheroid. If the difference is less than a predetermined threshold, the sensed electric field is ignored as being induced by a distant source. If the difference is greater than a predetermined threshold, the electric field sensed by the first and second conductive sensors is considered to be indicative of the presence of a foreign voltage on the conductor.

Abstract: A method of detecting the presence of a hazardous foreign voltage on a conductor includes the steps of sensing an electric field in the vicinity of the conductor with a first non-contact conductive sensor and sensing the electric field in the vicinity of the conductor with a second non-contact conductive sensor spaced a predetermined distance from the first non-contact conductive sensor. The difference between the electric field sensed by the first conductive sensor and the electric field sensed by the second conductive sensor is determined. The first conductive sensor preferably is shaped as a truncated spheroid. If the difference is less than a predetermined threshold, the sensed electric field is ignored as being induced by a distant source. If the difference is greater than a predetermined threshold, the electric field sensed by the first and second conductive sensors is considered to be indicative of the presence of a foreign voltage on the conductor.