ASTM D-495 and UL 746A
High Voltage Low Current Dry Arc Resistance
Evaluates a material’s resistance to surface tracking under a high-voltage, low-current arc at 12.8kV and 10-40mA.
Preferred Specimens: One test means up to 5 tests on a single material; the five tests can be conducted on different individual test specimens or on a single test specimen if the separation between the test locations is sufficient to avoid damage of one test to the surface of another test location. A minimum of 5 specimens are recommended. The preferred test specimen(s): approximately 3 mm (0.125 inch) thick and 100 x 100 mm (4 x 4 inch) flat plaque.
ASTM D-3638 and IEC 60112
Comparative Tracking Index (CTI)
Evaluates a material’s resistance to surface tracking within an intermittently-wet environment
Capability to test at up to 1000VAC.
Preferred Specimens: The preferred test specimens are 100 mm (4 inches) diameter disks with a minimum thickness of 2.5 mm (0.100 inches). A minimum of 5 specimens per material per thickness must be tested, however, that number is only sufficient if the number of drops falls exactly in line with expectations. The recommended minimum number of samples is 20 samples; the preferred number of samples for each material is 25. The condition of the surface of the material will greatly effect the results. All test specimens should be free of surface imperfections such as scratches and bubbles. The surface to be tested must be specified.
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Inclined Plane Time-To-Track
Evaluates a material’s resistance to surface tracking under constantly-wet, contaminated conditions
Tests performed up to 6000VAC.
Preferred Specimens: Flat surface approximately 2 by 5 inches (50mm by 130mm) and of a thickness rigid enough to support itself without flexing or bending.At least 5 specimens per material per thickness to be tested must be provided; the preferred number is 7 specimens.
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Dust–and–Fog Tracking and Erosion Resistance of Electrical Insulating Materials
This test method evaluates the tracking resistance of a material in a continually wet and dusty environment. This is the most harsh of the most common track resistance tests. This method evaluates surface tracking and erosion through the material.
Preferred Specimens: A single “test group” = 3. Dimensions: Approximately 150 x 150 mm and minimum of 1.5 mm, not to exceed 6 mm thick.