Abstract: The error correction method in the measurement of impedance and power factor is introduced.Both the primary correction method and the accurate correction method are discussed mainly and the modified formula for calculating the impedance and power factor is obtained.An example for measuring the impedance and power factor of the fluorescent lamp circuits is shown.It is seen from the results that there is a large difference between the results of the accurate amendment and the uncorrected case,so a more accurate measurement is required,then the measurement results should be corrected.

Key words: impedance, power factor, error correction