Hot Line
400-800-6106
The comparative tracking index (CTI) is a measure of how well a solid insulating material withstands tracking, the progressive formation of conductive paths on a surface exposed to moisture and contamination. It matters because creepage distances in safety standards are set according to the material group, and the material group is derived from the CTI.
The test is defined in IEC 60112 and its EN and GB equivalents. Fifty drops of a specified electrolyte solution fall at a controlled rate onto the surface between two platinum electrodes, and the voltage is adjusted until tracking occurs in a defined proportion of the fifty-drop applications. The result is expressed as a CTI value in volts, which places the material in group I, II, IIIa or IIIb.
NTEK tests insulating materials used in connectors, terminal blocks, printed circuit boards, switchgear and appliance housings, and issues reports suitable for safety certification submissions.