International Electrotechnical Commission <br/><br/>
IEC: 51-9-1988 (Amendment No.1 - 1994); Amendment 1Direct Acting Indicating Analogue Electrical Measuring Instruments and their Accessories Part 9 Recommended Test Methods 

 - Geneva  IEC  1997 
 - 3p 
<br/><br/><label>Universal Decimal Class. No.: </label> /