International Electrotechnical Commission <br/><br/>
IEC: 51-3-1984 (Amendment No.1 - 1994); Direct Acting indicating Analogue Electrical-Measuring Instruments and their Accessories Part 3 Special Requirements for Wattmeters and Varmeters 

 - Geneva  IEC  1994 
 - 3p 
<br/><br/><label>Universal Decimal Class. No.: </label> /