Revision Standard - Active.Supersedes C37.26-1972 (R1996). Abstract: This guide provides methods for determining the value of power factor for inductive low-voltage (1000 volts ac and below) test circuits. These methods are used in determining power factor during short-circuit current tests in high power laboratories. It is preferred that these methods be used during short-circuit current testing. Alternatively, other methods (including use of computerized or digital techniques) may be used, but the method used must have been validated as producing results equivalent to those obtained using the methods in this guide. The methods described are intended for use in low-voltage test circuits (under 1000 volts ac), but may also be used for higher voltages.