To reduce error due to voltmeter non-ohmic contacts, use shielding and appropriate grounding to reduce ac pickup.
为了降低电压表的非欧姆接触所产生的误差，采用屏蔽和适当的接地措施来降低交流干扰。
2
At the same time CCD pickup camera and laser sensor are combined to meet the high efficiency and high accurateness requirements of this non-contact measure.