Power factor measurement by the capacitance bridge

SEVERAL types of capacitance bridge for the measurement of both capacitance and power factor of dielectric specimens are in use at the present time. Some of these make a direct comparison between the capacitance under test and a standard capacitance. For accurate power factor measurements upon dielectric specimens at low voltages and audio frequencies, however, a substitution method is generally preferred. Two substitution methods which may be referred to as the 1 direct” and the “parallel” are commonly employed. With each method, a small change in the phase angle of the arm of the bridge circuit in which the substitution is made occurs. The compensation for this change enters directly into the measurements, and the essential differences between bridges in common use is in the manner of making this adjustment.