Process and Practical Experience of Measuring Resistance with a Multimeter
① First select a resistance range (×1, ×10, ×100, ×1 k, etc.). Short‑circuit the two test leads, then turn the zero‑ohm adjustment potentiometer to set the pointer to the 0‑Ω mark. This procedure is known as ohm zero adjustment.
② Connect the two test leads to both terminals of the resistor under test. (Make sure this resistor is disconnected from any other circuit.) The resistance value equals the pointer reading multiplied by the range multiplier.
Example: When using the ×100 range, if the pointer points to 20, the result is 20 × 100 = 2000 Ω.
Practical Testing Tips
① The ohm‑scale is non‑linear; its middle section has finer graduations. For higher accuracy, try to keep the pointer within the 20 %‑80 % segment of the full‑scale range. Depending on the tolerance grade of resistors, readings are allowed to deviate ±5 %, ±10 % or ±20 % from the nominal value. If the deviation exceeds these limits, the resistor has drifted in value.
② During measurement, especially for resistors of several tens of kilo‑ohms or higher, avoid touching the conductive parts of test probes and resistors with your hands. The resistor under test should be removed from the circuit, with at least one lead disconnected, to prevent measurement errors caused by other circuit components. Although resistance values of color‑band resistors can be identified from color rings, it is best to measure their actual resistance in practical use.
For cement resistors, which are fixed resistors, the measurement method is identical to that for ordinary fixed resistors.
