What is a IEC60112 PTI and CTI Tracking Index Test Machine?

In the realm of electrical and electronic engineering, ensuring the safety and reliability of materials is paramount. One critical aspect of this is understanding the comparative tracking index (CTI) and proof tracking index (PTI) of insulating materials. These indices are essential for determining the resistance of materials to electrical tracking, which can lead to failures and hazards in electrical equipment. The IEC60112 standard provides a comprehensive method for measuring these indices, and specialized equipment known as PTI and CTI tracking index test machine are used to perform these tests.

1. Understanding of PTI and CTI

Proof Tracking Index (PTI): PTI is a measure of the electrical breakdown resistance of an insulating material under specific test conditions. It indicates the maximum voltage at which a material can withstand a specified number of drops of a contaminant solution without forming a conductive track.

Comparative Tracking Index (CTI): CTI, on the other hand, is a more rigorous test that determines the voltage at which a material will fail due to tracking after 50 drops of the contaminant solution. CTI values are used to classify materials into different performance categories, which are crucial for selecting the right materials for specific applications.

2. Main Standard IEC60112

The tracking index tester is fully designed according to IEC60112 standard. The IEC60112 standard, developed by the International Electrotechnical Commission (IEC), outlines the test method for determining the PTI and CTI of solid insulating materials. The standard specifies the test apparatus, test conditions, and procedures to ensure consistent and reliable results. Adhering to this standard is essential for manufacturers and testing laboratories to ensure that their materials meet the required safety and performance criteria.

3. PTI and CTI Tracking Index Tester

The PTI and CTI tracking index tester is a specialized device designed to perform the tests outlined in the IEC60112 standard. The tester typically consists of the following components:

1) Test Chamber: This is a controlled environment space where the test specimens are placed. The chamber is designed to maintain specific temperature and humidity conditions to ensure accurate and repeatable results.

2) Electrode Assembly: The electrodes are used to apply the test voltage to the specimen. The size of the electrodes is 2mm±0.1mm)×(5mm±0.1mm)×(40mm±5mm), length≥12mm, and with an angle of chisel-edged: 30°±2°. It usually made of platinum with a minimum purity of 99%.

3) Solution System: A device that delivers a precise number of drops of a standardized contaminant solution (usually ammonium chloride) onto the specimen at specified intervals.

4) High Voltage Power Supply: Provides the necessary voltage to the electrodes to induce tracking on the specimen. Normally the voltage can be set from 100V to 600V.

5) Monitoring and Control System: Modern testers are equipped with advanced monitoring and control systems that automate the test process, record data, and ensure compliance with the IEC60112 standard.

4. Importance of PTI and CTI Testing

PTI and CTI testing are critical for several reasons:

Safety: Ensuring that insulating materials can withstand electrical tracking is essential for preventing electrical fires and other hazards.

Reliability: Materials with higher CTI values are less likely to fail due to tracking, leading to more reliable and durable electrical equipment.

Compliance: Many industries and regulatory bodies require materials to meet specific PTI and CTI ratings to ensure compliance with safety standards.

5. Conclusion

The IEC60112 standard and the use of PTI and CTI tracking index testers play a vital role in the evaluation and selection of insulating materials. By understanding and applying these tests, manufacturers can ensure that their products are safe, reliable, and compliant with international standards. As technology advances, the development of more sophisticated testing equipment will continue to enhance the accuracy and efficiency of these critical evaluations.