DIN EN 60519-21:2009 Safety in electroheat installations - Part 21: Particular requirements for resistance heating equipment - Heating and melting glass equipment (IEC 60519-21:2008); German version EN 60519-21:2009
2009DIN EN 60519-21:2009 Safety in electroheat installations - Part 21: Particular requirements for resistance heating equipment - Heating and melting glass equipment (IEC 60519-21:2008); German version EN 60519-21:2009