Insulation Resistance Tester, Commonly Known as Megger or Megohmmeter, Is Used for Measuring Insulation of Electrical Equipment, Cables, and Motors
A professional instrument for measuring the resistance of insulation materials in equipment such as transformers, primarily used to evaluate equipment insulation performance and prevent safety incidents such as leakage and short circuits. Based on 2025-2026 market information, here is a detailed introduction, mainstream brands, and selection recommendations for insulation resistance testers: 1. Core Functions and Roles Insulation Performance Evaluation: Measures insulation material resistance values (typically in MΩ or GΩ) by applying high-voltage DC (such as 500V, 1000V, 2500V, 5000V, etc.). Fault Diagnosis: Detects insulation aging, moisture ingress, contamination, or mechanical damage. Absorption Ratio and Polarization Index: High-end models can automatically calculate the Dielectric Absorption Ratio (DAR) and Polarization Index (PI) for more accurate insulation condition assessment. Automatic Discharge: Automatically releases the charge on the tested equipment after testing to ensure operator safety. 2. 2026 Mainstream Market Brands and Models The market is currently divided into imported high-end brands and domestic cost-effective brands: International Renowned Brands Germany GMC (METRISO Series): Features: Extremely high accuracy, rugged and durable, suitable for harsh environments. Representative Models: METRISO BASE, METRISO TECH. Applications: High-end laboratories, demanding industrial sites. USA Fluke: Features: Easy operation, good safety, strong data recording capability. Representative Models: Fluke 1550C, Fluke 1587 FC. Japan Hioki / Kyoritsu: Features: Compact and portable, cost-effective, high market share in Asia. Representative Models: KEW 3431, KEW 3441. Domestic Well-Known Brands Kanggaote: Features: High recognition in the power industry in recent years, rich product lines, fast service response. Applications: Power system preventive testing. Boyu Electric (BY): Representative Model: BY2671 Series Digital Megohmmeter. Features: Cost-effective, suitable for routine project acceptance and maintenance. Reference Price: Approximately RMB 1,600. Other Manufacturers: Jiangsu Jiuyi, Wuhan Huadian, etc., providing specialized testers for specific scenarios (such as water-cooled generators). Special Applications: Hebei Woge, etc. provide explosion-proof insulation resistance testers suitable for hazardous environments such as mining and petrochemical industries. 3. Price Range Reference Entry-Level/Handheld: ¥500 - ¥2,000 (suitable for general electrical maintenance, lower voltage levels). Professional/Digital: ¥2,000 - ¥8,000 (with auto-ranging, data storage, Bluetooth transmission, etc.). High-End/Specialized: ¥10,000 - ¥200,000+ (such as German GMC high-end models or large water-cooled generator specialized testers). 4. Selection Recommendations When selecting an insulation resistance tester, consider the following factors: Test Voltage Level: Select based on the rated voltage of the equipment under test. Low-Voltage Equipment (<500V): Choose 500V or 1000V range. High-Voltage Equipment (such as 10kV cables): Typically requires 2500V or 5000V range. Measurement Range: Ensure the instrument maximum resistance range meets requirements (e.g., whether 1TΩ measurement is needed). Functional Requirements: Whether automatic PI/DAR calculation is needed, whether data storage/upload is needed, whether strong anti-interference capability is needed (for VFD motor testing). Environmental Adaptability: Outdoor work requires attention to IP rating and drop resistance; flammable and explosive environments must use explosion-proof types. Standards Compliance: Confirm the instrument complies with the latest standards (such as IEC 61557, DL/T 596-2021, etc.).
