IDES > Resources > Plastic Material Properties > UL 746

Comparative Tracking Index (CTI) - UL 746 Test Standard Explained

Apply for Access to 84,000 Datasheets • Share this page

Property information for specific grades of resin are available in the Prospector Plastics Database.
Property Search let's you search for plastics by more than 400 material properties.

Comparative Tracking Index (CTI) - UL 746

The voltage which causes tracking after 50 drops of 0.1% ammonium chloride solution have fallen on the material. The results of testing at 3 mm thickness are considered representative of the material's performance in any thickness.

Tracking is an electrical breakdown on the surface of an insulating material. A large voltage difference gradually creates a conductive leakage path across the surface of the material by forming a carbonized track.

Performance Level Categories (PLC) were introduced to avoid excessive implied precision and bias.

Tracking Index (V)	PLC
600 and Greater	0
400 through 599	1
250 through 399	2
175 through 249	3
100 through 174	4
<100	5

Similar Standards

IEC 60112

Property information for specific grades of resin are available in the Prospector Plastics Database.