Method of high voltage detection and accurate phase angle measurement in cordless phasing meters

A high voltage phasing voltmeter comprising:

• a first high voltage probe comprising an electrode connected in series with a resistor, and a housing enclosing an electrical circuit for measuring line voltage of a first high voltage line, the electrical circuit comprising an input circuit for connection to the probe, the input circuit being adapted to suppress high frequency noise pick up by the probe and developing a voltage representing measured line voltage, an amplifier circuit with high common-mode rejection ratio connected to the input circuit, a signal processing circuit connected to the amplifier circuit for detecting measured line voltage and detecting zero crossings of the measured line voltage, and a communication circuit for transmitting the measured line voltage and detected zero crossings of the measured line voltage;
• a second high voltage probe comprising an electrode connected in series with a resistor, and a housing enclosing an electrical circuit for measuring line voltage of a second high voltage line, the electrical circuit comprising an input circuit for connection to the probe, the input circuit being adapted to suppress high frequency noise pick up by the probe and developing a voltage representing measured line voltage, an amplifier circuit with high common-mode rejection ratio connected to the input circuit, a signal processing circuit connected to the amplifier circuit for detecting measured line voltage and detecting zero crossings of the measured line voltage, and a communication circuit for receiving the measured line voltage and detected zero crossings of the measured line voltage from the first high voltage probe, the processing circuit determining phase relationships between the first and second high voltage lines and being connected to a display for displaying the phase relationships and measured line voltages.