If there is an ac potential difference between the shield and the measuring instrument, 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。

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Ac sampling measurement unit has better accuracy and stability as the online measuring instrument of the electrical parameters of power network.

交流采样测量装置作为电网电测量参数的在线测量仪器，具有较好的准确度和稳定性。

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