Formerly the arc length error for the insulation resistance instrument is defined by scale arc length. At present national standard determines that the percentage of indicated value expresses it.
绝缘电阻表以前是按标度尺弧长定义的弧长误差，现行国家标准规定以指示值的百分数表示。
2
The physical phenomenon of fault arc was described and the standard of the protection of fault arc was introduced.
在阐述故障电弧物理现象的基础上，介绍了故障电弧防护标准。
3
The national standard is suitable for welded joint of carbon steel and low alloy steel with gas welding (being used for sheet metal), manual arc welding and gas - shielded welding.