Notes on Measuring Resistance Using the Multimeter Resistance Range
① When the resistor is connected to a circuit, cut off the circuit power supply first. Never measure resistance on a live circuit. Live measurement may burn out the multimeter and produce inaccurate results.
② The positive terminal of the internal dry battery inside the multimeter connects to the "−" jack on the panel, and the negative terminal connects to the "+" jack. Pay attention to polarity when measuring resistance of polarized components such as electrolytic capacitors and transistors.
③ Re‑perform ohm zero adjustment every time you change the multiplier range.
④ Do not directly measure the internal resistance of high‑sensitivity meter movements with the multimeter resistance range. The resulting current (microampere level) through the meter movement may exceed its rated capacity and burn it out.
⑤ Do not grip the metal tips of both probes with your two hands during resistance measurement. Otherwise, human body resistance will be paralleled with the resistor under test and introduce measurement error. The reading obtained will be the equivalent resistance of the human resistance in parallel with the measured resistor instead of the true resistance of the component.
⑥ In‑circuit resistance measurement may bring large deviations. The measured value is the equivalent resistance formed by partial circuit resistors in parallel with the target resistor rather than the actual resistance of the component. It is recommended to desolder one pin of the resistor for measurement.
⑦ When measuring the equivalent resistance of non‑linear components with different ohm multipliers of the multimeter, different resistance readings will be obtained. This is caused by different mid‑scale resistance and full‑scale current for each range. For analog multimeters, generally the smaller the multiplier, the lower the measured resistance value (refer to sections about diodes and transistors for details).
⑧ Pay attention to probe polarity when measuring equivalent resistance of polarized components such as transistors and electrolytic capacitors (refer to the section on capacitor quality identification for details).
⑨ After finishing measurement, turn the selector switch to the maximum AC voltage range or the off position.
