IEC 61515:2016 establishes the requirements for simplex, duplex and triplex mineral-insulated metal-sheathed thermocouple cables and thermocouples, which are intended for use in general industrial applications. The abbreviation MIMS (for "mineral-insulated metal-sheathed") will be used hereafter. It covers thermocouple cables and thermocouples with only base-metal conductors of Types T, J, E, K and N. The specifications in this standard apply to new thermocouple cables and thermocouple units as delivered to the user. They do not apply to the product after use. This second edition cancels and replaces the first edition published in 1995. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - Duplex and triplex are standardized. - Specification of insulation resistance is revised so that the user can choose the best product to fit for the purpose. - "Table 2 Recommended maximum operating temperatures" in the previous version is expanded significantly including newly developed sheath material and it is moved to Annex C. - Test items and their methods are expanded and a guide table (Table 4) is added for userfriendliness.