High accuracy, strong anti-interference capability and high reliability for use in energy, communication and railway applications. Features and benefits - Gear-based measurement: multiple gear settings allow measuring voltage and resistance by changing gears. DY4100B includes a ground resistance measurement function. - PV voltage testing: open-circuit voltage range from -1500 V to 1500 V, enabling quick and accurate determination of PV module open-circuit voltage. - Grounding tests: during grounding resistance measurements, series interference voltage is automatically tested synchronously; abnormal results trigger an on-device warning message. 2-3 practical use scenarios - Solar installations: quickly verify PV module open-circuit voltage to assess module health and system performance. - Substations and industrial facilities: reliably measure grounding resistance and monitor interference conditions to ensure safe operation. - Field service for telecom and outdoor electrical systems: convenient voltage and resistance measurements across different circuits with built-in safety checks. This device emphasizes precise measurements, robustness in harsh environments, and practical applicability across energy, communications and railway settings, while maintaining a clear focus on function, compatibility with its intended measurement tasks, and reliable performance.