Precautions for Using Analog MF47 Multimeter
Precautions for Multimeter Use
(1) Before using the multimeter, perform "mechanical zero adjustment". That is, when no electrical quantity is being measured, the pointer of the multimeter should point to the position of zero voltage or zero current.
(2) While operating the multimeter, do not touch the metal parts of the test probes with your hands. This ensures measurement accuracy on one hand and guarantees personal safety on the other hand.
(3) When measuring an electrical quantity, do not switch ranges during measurement. This is especially critical when measuring high voltage or large current; otherwise, the multimeter may be damaged. If range switching is necessary, disconnect the test leads first, switch the range, and then resume measurement.
(4) The multimeter must be placed horizontally during use to avoid measurement errors. In addition, keep it away from the influence of external magnetic fields.
(5) After using the multimeter, set the selector switch to the maximum AC voltage range. If the meter will not be used for a long time, remove the internal battery of the multimeter to prevent battery corrosion of other internal components.
Use of the Ohm Range
① Select an appropriate magnification factor. When measuring resistance with the ohm range, choose a suitable multiplier so that the pointer falls near the middle scale value. Avoid using the left one-third section of the scale, as this region has poor scale density.
② Perform zero adjustment before use.
③ Do not measure live circuits.
④ The measured resistor must have no parallel branches.
⑤ When measuring the equivalent resistance of polarized components such as transistors and electrolytic capacitors, pay attention to the polarity of the two test probes.
⑥ When measuring the equivalent resistance of non-linear components with different ohm multipliers on a multimeter, the measured resistance values will differ. This is caused by different internal resistance and full-scale current of each range. For analog multimeters, generally the smaller the multiplier, the lower the measured resistance value.
