DIN EN 15502-2-2-2012 燃气中央供暖锅炉.第2-2部分:额定热输入不超过70 kW的B1型号用具专门标准.德文版本prEN 15502-2-2-2012
Gas-fired central heating boilers - Part 2-2: Specific standard for type B1 appliances of a nominal heat input not exceeding 70 kW; German version prEN 15502-2-2:2012