Operating Procedures for Resistance Measurement with a Multimeter
① Mechanical Zero Adjustment Place the multimeter as required (the MF47 model shall be placed horizontally). Check whether the pointer aligns with the zero mark on the left‑hand scale. If not, turn the mechanical zero‑adjustment screw with a flat‑head screwdriver to set the pointer to zero.
② Preliminary Test Turn the multimeter selector switch to the ohm ×100 range. Connect the red and black probes to the two pins of the resistor under test and observe the pointer position.
③ Select a Suitable Multiplier Choose a proper multiplier according to the pointer reading. (1) Criterion for multiplier selection: The pointer should fall near the mid‑scale position. Avoid the left one‑third of the scale, where markings are dense and readings carry large errors. Ideally, the pointer should land between 5 and 50 on the ohm scale. (2) Quick multiplier selection rule: If the reading is too high, increase the multiplier; if the reading is too low, reduce the multiplier. Note: "Too high" or "too low" refers to the target range of 5–50 on the scale. A reading to the right of 5 means the reading is too low; a reading to the left of 50 means the reading is too high.
④ Ohm Zero Adjustment After selecting the multiplier, perform ohm zeroing. Short the two probes together and rotate the ohm‑adjust knob until the pointer points to "0" Ω on the right end of the resistance scale.
⑤ Measurement and Reading Touch the red and black probes to the two ends of the resistor and read the resistance value. Reading method: Multiply the pointer reading by the selected multiplier to get the measured resistance. For example, if the R×100 range is selected and the pointer shows 40, the resistance value is 40 × 100 = 4000 Ω = 4 kΩ.
