从未使用和已使用绝缘油中腐蚀性硫化物定量测定试验方法.第2部分:总腐蚀硫（TCS）定量测定的试验方法

[中文适用范围]： IEC 62697的这一部分规定了通过将腐蚀性硫物质转化为金属（铜、银等）硫化物来定量测定未使用和使用过的绝缘液体和固体基质中总腐蚀性硫（TCS）的测试方法。形成的硫化物定量转化为硫酸盐；硫酸盐通过浊度测量或离子色谱法测定。该方法适用于以下基质： a) 未使用和使用过的绝缘液体，例如矿物绝缘油和天然酯，可以测定浓度范围为 2.5 mg kg-1 至 80 mg kg- 的腐蚀性硫化合物。 1 个TCS。 b) 与绝缘液体接触的固体基质，例如电气设备中的绝缘纸。这些基质的定量限取决于测定过程中使用的基质量。该方法可用于根据 IEC 62535 测试后对纸张上的硫化铜进行定量或半定量测定。该方法可以对纸张上存在的硫化铜进行明确的定量评估，而不是通过 SEM-EDX 检查获得的定性结果如果对根据 IEC 62535:2008, 6.3 进行的纸张检查结果的解释有疑问，请按照规定进行规定。 c) 从故障变压器、电抗器和其他电气设备中获得的纸和其他固体绝缘材料，以协助故障诊断。 d) 绝缘液体中存在金属钝化剂或钝化剂添加剂（定性评估）。然而，该方法不适用于评估腐蚀现象，例如铜在绝缘液体中的溶解和在固体基质上的沉积，这不会导致硫化物形成。 [外文原描述]： IEC TR 62697-2:2018(E) specifies a test method for the quantitative determination of total corrosive sulfur (TCS) in unused and used insulating liquids and solid matrices through the conversion of corrosive sulfur species to metal (copper, silver etc.) sulfides. The sulfides formed are quantitatively converted to sulfates; sulfates are determined through turbidity measurement or with ion chromatography. The method is applicable with the following matrices: a) Unused and used insulating liquids, for example mineral insulating oils and natural esters, which allow the determination of corrosive sulfur compounds over concentrations ranging between 2,5 mg kg-1 to 80 mg kg-1 TCS. b) Solid matrices that come in contact with the insulating liquid, for example insulating papers in electrical equipment. The quantification limits for these matrices depend on the amount of matrix used during the determination. The method can be used for the quantitative or semi-quantitative determination of copper sulfide on paper after the test according to IEC 62535. The method can provide unambiguous quantitative assessment of copper sulfide present on paper rather than qualitative results obtained with the SEM-EDX examination stipulated in case of doubts in the interpretation of results obtained from the inspection of paper according to IEC 62535:2008, 6.3. c) Paper and other solid insulating material/s obtained from failed transformers, reactors and other electrical equipment to assist in failure diagnostics. d) Metal deactivator or passivators additives present in insulating liquids (qualitative assessment). However, the method is not applicable for assessing corrosion phenomena for example the dissolution of copper in insulating liquids and deposition on solid matrices, which do not lead to sulfide formation.