Introduction to Precautions for Using a Digital Multimeter
① When measuring DC voltage above 36 V, AC voltage above 25 V, current above 10 mA, AC power lines with inductive loads, or AC power lines during power‑fluctuation periods, take strict precautions against electric shock.
② Before measurement, verify that the function selector switch is set to the correct range. Check that the test probes make reliable contact, are correctly connected, and have good insulation to prevent electric shock.
③ The instrument meets safety‑standard requirements only when used with its original supplied test probes. If the test‑probe wires are damaged, replace them with probes of the same model or identical electrical specifications.
④ Do not replace the internal fuse with unapproved fuses. Only install fuses of the same model or identical specifications. Before replacement, remove the test probes from the measured points to ensure no signal is present at the input terminals.
⑤ Do not replace the instrument battery with unapproved batteries. Only install batteries of the same model or identical electrical specifications. Before replacement, remove the test probes from the measured points to ensure no signal is present at the input terminals.
⑥ During electrical measurement, do not allow your body to make direct contact with earth ground. Avoid touching exposed metal terminals, output ports, alligator clips and other components that may carry ground potential. Use dry clothing, rubber‑soled shoes, rubber mats or other insulating materials to keep your body isolated from earth ground.
⑦ Do not store or operate the instrument in environments with high temperature, high humidity, flammable‑explosive atmospheres or strong magnetic fields.
⑧ Measuring voltages exceeding the instrument's rated maximum limit may damage the instrument and endanger personal safety. The maximum allowable measurement voltage is marked on the instrument panel. Never apply input signals exceeding this rated limit to avoid electric shock and instrument damage.
⑨ When test probes are plugged into the current‑input jacks, do not measure any voltage, which may damage the instrument and endanger operator safety.
⑩ Do not attempt to calibrate or repair the instrument. All calibration and repair work must be performed by specially‑trained, qualified and authorized professional personnel.
⑪ During measurement, the function‑range selector switch must be set to the correct range. Before switching the function‑range selector, disconnect the test probes from the device‑under‑test and ensure no input signal exists. Never toggle the function‑range selector while a measurement is in progress.
⑫ When the LCD shows low‑battery indication, replace the battery promptly to guarantee measurement accuracy.
⑬ Never measure voltage while the instrument is set to the current range.
⑭ Do not modify the internal circuitry of the instrument arbitrarily, otherwise instrument damage and safety hazards may occur.
