If there is an ac potential difference between the shield and the measuringinstrument, there may be capacitive currents flowing through the measuring circuit that will add interference.
如果屏蔽和测量仪器之间存在一个交流电势差，则可能有电容性电流通过测量电路，增大干扰。
2
Ac sampling measurement unit has better accuracy and stability as the online measuringinstrument of the electrical parameters of power network.