Technical Support

What is Comparative Tracking index (CTI)?

Comparative Tracking Index is expressed as that voltage which causes tracking after 50 drops  of 0.1 percent ammonium chloride solution have fallen on the material. The results of testing the nominal 3 mm thickness are considered representative of the material's performance in any thickness.
CTI RANGE
Tracking Index (in Volts)
 PLC Assigned
600 and greater 0
400 ~ 599 1
250 ~ 399 2
175 ~ 249 3
100 ~ 174 4
Less than 100 5