The influence of signal pick-up method on measuring precision of tan δ with a quasi-synchronous sampling harmonic analysis method

The paper introduces the measurement of tan δ with a quasi-synchronous sampling harmonic analysis method firstly. The principle and the algorithm for harmonic analyzing under the condition of quasi-synchronous sample are described. It is shown, through an analysis about many influencing facts, that this method has high precision and good anti-disturbance characteristics, but the precision of this method is influenced by the methods of signal pick-up. The paper analyses the influence of different methods of signal pick-up on the precision of measurement.