Designed specifically for laboratories, industrial sites, and educational demonstrations, the 3/2/4/2 digital DC millivolt/volt meter can achieve stable measurement with a resolution of μ V level and a basic accuracy of ± 0.05% in three low voltage ranges of 0-200 mV, 0-2 V, and 0-20 V, helping users quickly and intuitively obtain low-noise and low drift voltage data. Typical applications: College physics experiments: verifying Ohm's law, measuring parallel branch voltage; Battery capacity division: Single lithium battery 0-5V precision sorting; Sensor calibration: thermocouple, pressure sensor mV level output acquisition; Industrial site: PLC analog input circuit inspection, DCS I/O channel comparison; Maintenance and inspection: troubleshooting of low voltage nodes on the motherboard and power board.