BENETECH GT5105A Professional LCD Digital Resistance Tester Meter Megger Earth Ground Resistance Voltage Tester This instrument is controlled by intelligent microcontroller chip, with high accuracy and high reliability; it can be used to measure grounding resistance of various power facilities wiring, electrical equipment, fulmination protection equipment and other grounding devices, and it can also measure ground voltage. (Note: This instrument is not suitable for harsh outdoor environmental conditions, such as raining, lightning, etc.) Functions 1. Backlight and battery detection function. 2. Data holding. 3. It can be used for precise three-wire measurement or simple two-wire measurement. 4. When measuring ground resistance, if C or E end of test lead is not in good contact, "---- ohm" warning appears on LCD. 5. "OL" stands for over range. 6.Double insulation or reinforced insulation safety structure 1. Measurement method: - Ground voltage measurement: Average response - Ground resistance measurement: Test signal frequency: about 820Hz, current: 20 ohm about 3.2mA 2. Working environment: Temperature: 5~ 40 degree C, Relative humidity: Less than or equal 80 ~ RH (no fog) Altitude Less than or equal 2000 meters 3. Storage conditions: Temperature: -20 ~ 60 degree C; Relative humidity: Less than or equal 70% RH (no fog) 4. Power supply: 9V power supply: 1.5V (No. 5 alkaline battery) * 6 (Not included battery) 5. Overload protection: Ground resistance: 200V AC (10 seconds) Ground voltage: 400V AC (30 seconds) 6. Insulation resistance: The insulation resistance between measurement circuit and case is not less than 20Mohm