North Guangjingyi BL Comparative Tracking Index (CTI) Tester for Solid Insulating Materials

Overview

The North Guangjingyi BL Comparative Tracking Index (CTI) Tester is an engineered solution for evaluating the resistance of solid insulating materials to electrical tracking and erosion under contaminated, humid conditions. Based on the principle of controlled electrolyte droplet application across a high-voltage stress field, the instrument quantifies the material’s ability to resist the formation of conductive carbonized paths—commonly known as “tracking”—which can lead to insulation failure in real-world electrical equipment. This test method adheres strictly to the comparative tracking index (CTI) and proof tracking index (PTI) determination protocols defined in IEC 60112:2003 and GB/T 6553–2003. The device operates by applying alternating voltage (100–600 V AC) across two stainless-steel electrodes spaced 50 ± 0.5 mm apart, while standardized sodium chloride or ammonium chloride solution is dripped onto the specimen surface at programmable intervals. The CTI value—the highest voltage at which no tracking occurs within 50 drops—is determined through sequential testing and validated pass/fail criteria.

Key Features

• Five-channel parallel testing architecture: Enables simultaneous evaluation of up to five specimens under identical environmental and electrical conditions—significantly improving throughput and inter-sample comparability.
• Siemens PLC-based control system with optical isolation: Ensures galvanic separation between high-voltage circuits and signal acquisition modules, minimizing electromagnetic interference and guaranteeing stable, repeatable current and voltage monitoring.
• 9-inch industrial-grade touch HMI interface: Provides real-time visualization of leakage current per channel, voltage status, drip timing, elapsed test duration, and alarm events—without requiring external PCs or software.
• Independent per-channel over-current protection: Each test station features user-definable leakage current thresholds; exceeding the limit triggers immediate local high-voltage disconnection without interrupting ongoing tests on other channels.
• Adjustable electrochemical stress parameters: Drip volume, interval, test voltage (coarse manual knob + fine digital setting), and total test duration are fully configurable to align with material class requirements or internal QC protocols.
• Integrated safety enclosure: ≥0.75 m³ chamber with tempered glass observation window, built-in ventilation exhaust, and LED illumination—designed to contain aerosolized electrolyte and maintain operator safety during extended operation.

Sample Compatibility & Compliance

The BL CTI Tester accommodates standard rectangular specimens (typically 100 mm × 100 mm × 3–6 mm) made from thermoplastics, thermosets, laminates, and filled composites used in connectors, housings, circuit breakers, and PCB substrates. It supports both CTI (Comparative Tracking Index) and PTI (Proof Tracking Index) determinations per IEC 60112:2003 Annex A and B. The system meets full mechanical and electrical requirements of GB/T 6553–2003 (identical to IEC 60587:1984), UL 746A Section 20, ASTM D3638–92 (Standard Test Method for Determining Comparative Tracking Index of Solid Electrical Insulating Materials), and DIN 53480. All critical components—including electrode geometry, filter paper specifications (0.15–0.17 mm thickness, ISO-standard cut), and short-circuit verification (≥60 mA for ≥2 s)—are traceably aligned with these standards. The apparatus is suitable for laboratories operating under GLP or pre-GMP quality systems where audit-ready test execution and parameter logging are required.

Software & Data Management

While the BL model operates via embedded HMI without dependency on PC-based software, all operational parameters—including applied voltage, actual measured voltage drop, real-time leakage current (per channel), drip count, elapsed time, and alarm timestamps—are logged internally with millisecond-level resolution. Data export is supported via USB flash drive in CSV format for post-test analysis in Excel or LIMS environments. The system supports optional firmware upgrades for enhanced traceability, including configurable audit trails that record operator ID, parameter changes, and emergency shutdown events—facilitating compliance with FDA 21 CFR Part 11 principles when deployed in regulated manufacturing settings. No cloud connectivity or remote access is implemented, preserving data sovereignty and network security.

Applications

• Qualification of polymer compounds for high-voltage terminal blocks, relay bases, and motor control units.
• Material screening during formulation development of flame-retardant engineering plastics (e.g., PBT, PA66, PC blends).
• Production lot release testing per internal specifications aligned with IEC/UL CTI classification tiers (e.g., CTI ≥ 600 for “Class IIIa” applications).
• Root cause analysis of field failures linked to surface tracking in outdoor insulators or EV battery enclosures.
• Supporting technical documentation for CE marking, UL recognition, or CCC certification submissions.

FAQ

What standards does the BL CTI Tester fully comply with?
IEC 60112:2003, IEC 60587:1984, GB/T 6553–2003, UL 746A, ASTM D3638–92, and DIN 53480.
Can the instrument perform both CTI and PTI tests?
Yes—both test modes are supported via configurable voltage ramping, drop count limits, and pass/fail logic per IEC 60112 Annexes A and B.
Is calibration certification included with delivery?
The unit ships with factory calibration records for voltage output, timer accuracy, and drip volumetric consistency; third-party accredited calibration is available upon request.
What maintenance is required for long-term reliability?
Routine cleaning of electrodes and drip nozzles with isopropyl alcohol, annual verification of optical isolation integrity, and biannual inspection of filter paper feed mechanism.
Does the system support automated reporting?
Raw CSV logs enable automated report generation via external scripts; no built-in PDF or branded report engine is provided.