12 points for multimeter use precautions
1. Before use, check whether the pointer is at zero position. If not, adjust the pointer zero adjuster first.
2. According to the different properties of the measured object, adjust the transfer switch to the corresponding position. Pay special attention to the fact that when measuring voltage, do not place the transfer switch in the current or resistance position, otherwise the multimeter will be burned out.
3. When measuring DC current or DC voltage, insert the red meter stick into the red or "+" symbol jack, and connect the other end to the positive pole of the measured object; insert the black meter stick into the black or "one" symbol jack. 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, and the reading is more accurate at this time. If the measured size is not known in advance, in order to avoid damage to the multimeter due to the selection of too small a range, you should select the maximum range prediction of this type, and then select the appropriate range to reduce the measurement error.
6. There are multiple scales on the dial of the multimeter, which represent different measurement types. When measuring, read on the corresponding scale according to the type and range selected by the transfer switch, and pay attention to the magnification relationship between the selected range and the reading on the scale.
7. When measuring resistance, you should choose a suitable magnification position. Since the scale of the resistance file is in the opposite direction of the scale, and the scale is uneven, the farther to the left, the denser the scale and the worse the measurement accuracy, so the pointer should be deflected at Where the scale is thinner, it is advisable to deflect near the middle of the scale.
8. Before measuring the resistance, zero adjustment should be carried out, short the red and black gauge sticks, and turn the ohm zero adjustment knob at the same time, so that the pointer points to the "0" mark line of the resistance scale. Every time the magnification gear is changed, it should be zeroed before measurement. If the pointer cannot be adjusted to the zero position, the battery should be replaced with a new one.
9. When measuring resistance, at least one end of the measured resistance is disconnected from the circuit and the power supply is cut off before measurement can be performed.
10. When measuring higher voltage and larger current, the switch knob cannot be turned with power on to ensure personal safety.
11. After each measurement, the transfer switch should be placed at the highest level of AC voltage, or placed in neutral, so as not to be misused by others and damage the multimeter.
12. If the multimeter is not used for a long time, the battery in the meter should be taken out to prevent the battery from corroding and damaging other components.
