DIN EN 60051-3/A1-1995 直接作动显示模拟电气测量仪器及其附件.第3部分:功率表和无功功率表特殊要求
Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters (IEC 60051-3:1984/A1:1994); German version EN 60051-3:1989/A1:1995