Simple new power-factor meter utilising dry-reed relays

The paper describes a simple, low-cost meter for the measurement of single-phase and 3-phase power factor on a linear scale. The meter is shown to be particularly suitable for use on widely varying levels of current and voltage. The basic single-phase meter is described first, and the modification necessary to give balanced 3-phase operation is shown to be sufficiently simple to permit single-phase and 3-phase measurements to be made using the same scale, terminals and ranges.