IEC 60112:2025 pdf download – Method for the determination of the proof and the comparative tracking indices of solid insulating materials.
IEC 60112:2025 specifies the test method for determining the proof tracking index (PTI) and comparative tracking index (CTI) of solid insulating materials, using specimens taken from equipment parts or from plaques of material under alternating voltage. The document includes a procedure for measuring erosion where required. The PTI serves as both an acceptance criterion and a quality-control measure for materials and manufactured parts, while the CTI is primarily used for basic characterization and comparison of material properties. This test method assesses both the material composition and the surface condition, since both factors directly affect test outcomes and must be considered during material selection. The procedure is intended for test voltages up to 600 V AC, as higher AC voltages and DC voltages reduce test severity.