Comparative Tracking Index measures resistance to surface tracking on insulating materials. Higher CTI classes support smaller creepage paths in many equipment standards. Results are specific to a material grade and thickness. When you select covers shields and plates near live parts it helps to choose materials with appropriate CTI class and to document the grade used in production.
CTI is determined by a standardized test that applies a contaminant and voltage to the material surface. The measured value places the material into a CTI class. A higher class indicates greater resistance to tracking. Use CTI together with creepage and clearance design rules from your product standard. We can help align material choice with your required class.
Near busbars or terminals a higher CTI class can allow more compact layouts within the rules of the product standard. Always confirm that the grade used in production matches the CTI value in design documentation. We can propose available grades and keep the traceability clear from sheet supply to finished parts.
We supply a Certificate of Conformity for fabricated parts and can share supplier data sheets and test reports where available for the selected grade. Keeping a clear record of grade color and thickness supports audits and repeat orders. Ask us for a material and document pack with your shipment.
