12 points to note when using a multimeter
1. Before use, check whether the pointer is at zero position. If it is not at zero position, adjust the pointer zero adjuster first.
2. According to the different properties of the measured object, adjust the switch to the corresponding position. Pay special attention to the fact that when measuring voltage, the switch must not be placed in the current or resistance position, otherwise the multimeter will be burned out.
3. When measuring DC current or DC voltage, the red meter rod should be inserted into the red or jack with a "+" symbol, and the other end should be connected to the positive pole of the object being measured; the black meter rod should be inserted into the black jack or the jack with a "-" symbol. jack, and the other end is connected to the negative pole of the object under test.
4. When measuring current, the multimeter should be connected in series in the circuit under test; when measuring voltage, the multimeter should be connected in parallel in the circuit under test.
5. When measuring voltage and current, the pointer should be within the range of 1/2-2/3 of the full scale. At this time, the reading will be more accurate. If the size to be measured is not known in advance, in order to avoid damaging the multimeter by choosing too small a range, the maximum range prediction of this type should be selected, and then the appropriate range should be selected to reduce the measurement error.
6. There are multiple scales on the multimeter's dial, which represent different types of measurements. When measuring, you should read on the corresponding scale according to the type and range selected by the conversion switch, and pay attention to the magnification relationship between the selected range and the reading on the scale.
7. When measuring resistance, the appropriate magnification position should be selected. Since the scale of the resistance scale is in the reverse scale direction and the scale is uneven, the further to the left, the denser the scale and the worse the measurement accuracy, so the pointer should be deflected at The scale is sparse, and it is better to deflect it near the middle of the scale.
8. Before measuring resistance, zero adjustment should be performed. Short-circuit the red and black meter rods, and turn the ohm zero adjustment knob at the same time to make the pointer point to the "0" line on the resistance scale. Every time you change the magnification gear, you should first adjust it to zero before measuring. If the pointer cannot be adjusted to zero, the battery should be replaced with a new one.
9. When measuring resistance, at least one end of the resistance being measured must be disconnected from the circuit and the power supply must be cut off before measurement can be made.
10. When measuring higher voltages and larger currents, do not turn the switch knob while it is powered to ensure personal safety.
11. After each measurement, the transfer switch should be placed at the highest AC voltage level or in neutral to prevent others from misusing it and damaging the multimeter.
12. If the multimeter is not used for a long time, the battery inside the meter should be removed to prevent the battery from corroding and damaging other components.
