1.1 本试验方法包括测定纸和纸板中的含氮有机材料，这些材料通常用于减少纸和纸板中纤维素的热降解。 1.2 该方法测定的氮不包括硝基化合物、硝酸盐、亚硝酸盐、偶氮、肼、氰化物或吡啶环类化合物中的氮，这些化合物通常不存在于纸和纸板中。没有适用于所有含氮化合物的已知方法修改。 1.3 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本试验方法的目的是测定电绝缘纸或纸板样品中存在的有机氮量。氮含量用于确定纸张或纸板是否经过化学处理以承受高于正常工作温度。这种纸或纸板在业内被称为“热升级”经过热升级的纸张或纸板可以承受更高的工作温度，并使电气设备具有更长的使用寿命。

1.1 This test method covers the determination of nitrogenous organic materials in paper and paperboard, which typically are used to reduce the thermal degradation of the cellulose in the paper and paperboard. 1.2 The nitrogen determination by this method does not include the nitrogen in nitro compounds, nitrates, nitrites, azo, hydrazine, cyanide, or pyridine ring-type compounds, none of which are normally found in paper and paperboard. There is no known modification of the method that is applicable to all nitrogenous compounds. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 The purpose of this test method is to determine the amount of organic nitrogen present within a sample of electrical insulation paper or paperboard. Nitrogen content is used to determine if the paper or paperboard has been chemically treated to withstand higher than normal operating temperatures. Such a paper or paperboard is referred to in the industry as “thermally upgraded.” A paper or paperboard that is thermally upgraded can withstand higher operating temperatures and allow the electrical equipment to have a longer useful life span.