Comparative Tracking Index (CTI) Test Device.

The Comparative Tracking Index (CTI) Test Device is used to determine the tracking resistance of solid insulating materials under humid conditions. Specifically, it tests whether electrical conductive paths form on the surface of the insulating material. This device conducts tests in accordance with specific standards and plays a critical role in assessing the safety performance of insulation materials.

Applicable Standards:

The CTI Test Device adheres to the following standards:

• IEC 60112: Method for determining the comparative and proven tracking index of solid insulating materials.
• UL 746A: Evaluates the electrical properties of plastic materials.
• ASTM D3638: Similar tests for electrical insulation materials.
• EN 60112 / DIN EN 60112: European standard equivalent to IEC 60112.
• TSE (TS EN 60112): In Turkey, the test is conducted in compliance with IEC 60112.

Test Procedure:

After adjusting the test parameters and placing the sample on the test table shown on the computer screen, you can begin the test.

Required Parameters:

• Voltage Test
• Maximum Current
• Current Limit Error
• Number of Drops (N drops)
• Time Between Drops
• Maximum Duration of Fault Current
• Report Number
• Customer Name

After adjusting all test parameters, click the Test button. The system will perform the following steps:

1. Operate the relay to short-circuit the electrodes and measure the current.
2. Increase the voltage between the electrodes until it reaches the set voltage.
3. Increase the current until it reaches the set maximum current on this screen.
4. Close the short-circuit relay.
5. Begin dropping droplets at specific intervals.
6. Measure the current and voltage for each droplet.

Standard reference

The Comparative Tracking Index is determined to IEC 60112: drops of a defined electrolyte are applied between two electrodes on the material surface at increasing voltage until tracking occurs; the CTI is the highest voltage (in volts) at which the material withstands 50 drops without tracking, characterising its resistance to surface tracking.