IEC TR 62697-2:2018 

Test methods for quantitative determination of corrosive sulfur compounds in unused and used insulating liquids - Part 2: Test method for quantitative determination of total corrosive sulfur (TCS)


Do you need a multi-user copy?




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.

Look inside

Additional information

Publication typeTechnical Report
Publication date2018-02-14
Available language(s)English
TC/SCTC 10 - Fluids for electrotechnical applicationsrss
ICS29.040.10 - Insulating oils
Stability date  2024
File size1241 KB

The following test report forms are related:

Related publications

Share this page

Share your publications

Learn how to share your publications with your colleagues, using networking options.

Payment information

Our prices are in Swiss francs (CHF). We accept all major credit cards (American Express, Mastercard and Visa), PayPal and bank transfers as form of payment.

Keep in touch

Keep up to date with new publication releases and announcements with our free IEC Just Published email newsletter.

Contact customer services

Please send your enquiry by email or call us on +41 22 919 02 11 between 09:00 – 17:00 CET Monday to Friday.