根据标准GB/T 7602.3-2008和DL/T 929-2018,采用傅里叶变换红外光谱仪,分别用光程为0.1 mm和0.5 mm的KBr吸收池测定绝缘油结构族组成和T501抗氧化剂含量,对检测结果的差异性进行分析。结果表明:两种光程吸收池测定绝缘油的结构族组成结果符合DL/T 929-2018的再现性要求,并且不存在显著性差异,而0.5 mm光程吸收池测得的芳香烃和烷链烃的吸光度更大,适用于绝缘油结构族组成的准确测定;两种光程吸收池测定绝缘油中T501抗氧化剂含量结果偏差较大,不符合GB/T 7602.3-2008的再现性要求,而0.5 mm光程吸收池测得的T501抗氧化剂的峰形较好,无吸收干扰,适用于绝缘油中T501抗氧化剂含量的测定,并且采用峰面积定量所得结果的再现性相对较好。

According to the standards of GB/T 7602.3-2008 and DL/T 929-2018, Fourier transform infrared spectrometer was used to detect the structure group composition and antioxidant T501 in insulating oil using KBr absorption cells with optical path lengths of 0.1 mm and 0.5 mm, and the difference of detection results was analyzed. It was shown that the results of structure group composition in insulating oil using the absorption cells with two optical path lengths met the reproducibility requirements from DL/T 929-2018, and there was no significant difference. However, the absorbance of aromatic hydrocarbons and alkane chain hydrocarbons under the optical path length of 0.5 mm was higher, which was suitable for the accurate determination of the structure group composition in insulating oil. The determined results of T501 antioxidant in insulating oil using the absorption cells with two optical path lengths had large deviation, which not met the reproducibility requirements from GB/T 7602.3-2008. However, under the optical path length of 0.5 mm, T501 antioxidant had higher absorbance and better peak shape, and there was no absorption interference, which was more suitable for the determination of T501 antioxidant in insulating oil, and the reproducibility of quantitative results obtained by peak area was relatively good.