Insulation resistance tester is a special instrument for measuring insulation resistance. It is an ideal test instrument for measuring insulation resistance of large transformers, transformers, generators, high-voltage motors, power capacitors, power cables, arresters, etc. Features: Automatic release voltage function. Suitable for measuring insulation resistance of various electrical equipment and insulating materials such as transformers, motors, cables, switches, electrical appliances, etc. It is suitable for the maintenance, repair, test and verification of various electrical equipment. Rated output voltage variable: The rated output voltage can be switched by the function buttons( 1000V switches between 50V, 100V, 250V, 500V, 1000V; 2500V switches between 100V, 250V, 500V, 1000V, 2500V) Automatic shutdown function. When the instrument is out of operation for about 15 minutes, the instrument will automatically shut down to save battery power. Low battery voltage indication. Battery-driven, easier to use. Easy to operate and carry. Strong load capacity, about 3 mAh output short-circuit current. Complete protection circuit, not afraid of voltage counterattack, output short circuit protection. Dust-proof and moisture-proof structure, suitable for outdoor operation. Specifications: Model: HT5203 / HT5205 (Optional) In accordance with IEC/EN 61010-1 1000V CAT III, 600 V CAT IV measurement standards. 1000V DC, 750V AC (Sine wave) Insulation Test Measurement Range: HT5203: 3.00M~100.0G / HT5205: 3.00M~200.0G Insulation Resistance Test Voltage: HT5203: 50, 100, 250, 500, 1000 V / HT5205: 100, 250, 500, 1000, 2500 V Accuracy of Insulation Resistance Test Voltage: ±10 % TheInsulationShort-circuitTestCurrent:about3.0mA Maximum Capacitive Load for Insulation Testing: 1F Storage Temperature: -20°C~60°C Operating Temperature: 0°C~40°C Operating Altitude: 2000m CAT III 1000V; 3000m CAT II 1000V. Temperature Coefficient: for temperatures below 18 °C or above 28 °C, the coefficient is per (°C) x 0.05 x specified accuracy Relative Humidity: 40%~75% Batteries: 8 x 1.5V AA (LR) batteries(not included) Material: polycarbonate(PC) Item Size: 180 * 140 * 65 mm / 7.09 * 5.51 * 2.56 inch Item Weight: 627g / 22.12oz Package Size: 33.5 * 27 * 9.5 cm / 13.19 * 10.63 * 3.74 inch Package Weight: HT5203: 1338g / 47.2oz; HT5205: 1376g / 48.54oz Package List: 1 * Insulation Resistance Tester 1 * Test Pen 1 * Test Clamp 1 * Bag 1 * User Manual (English)