交流1 000 V和直流1 500 V以下低压配电系统电气安全 防护措施的试验、测量或监控设备 第4部分:接地电阻和等电位接地电阻
Electrical safety in low voltage distribution systems up to 1 000 V a.c—Equipment for testing, measuring or monitoring of protective measures—Part 4:Resistance of earth connection and equipotential bonding