Precautions for using a multimeter 12 key points
1. Before use, check whether the pointer is at zero position. If it is not, adjust the pointer zero adjuster first.
2. Adjust the transfer switch to the corresponding position according to the different measured properties. Special attention should be paid when measuring voltage, and the conversion switch should not be placed in the current or resistance range, otherwise it may burn out the multimeter.
3. When measuring DC current or DC voltage, the red meter rod should be inserted into the red or "+" symbol socket, and the other end should be connected to the positive pole of the tested object; Insert the black watch rod into the black or "one" symbol socket, and connect the other end to the negative electrode of the tested object.
4. When measuring current, a multimeter should be connected in series in the circuit being tested; When measuring voltage, a multimeter should be connected in parallel in the circuit being tested.
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 should be more accurate at this time. If the measured size is not known in advance, in order to avoid damaging the multimeter by selecting too small a range, the maximum range prediction of that type should be selected, and then a suitable range should be selected to reduce measurement error.
6. There are multiple scales on the dial of the multimeter, representing different types of measurements. When measuring, readings should be taken on the corresponding scale based on the type and range selected by the conversion switch, and attention should be paid to the ratio relationship between the selected range and the reading on the scale.
7. When measuring resistance, a suitable magnification position should be selected. Due to the fact that the resistance scale is in the opposite direction of the scale and the scale is uneven, the closer it is to the left, the denser the scale, and the lower the measurement accuracy. Therefore, the pointer should be deflected at the thinner part of the scale, and it is advisable to deflect it close to the middle of the scale.
8. Before measuring resistance, zero adjustment should be carried out by short circuiting the red and black gauge rods, and rotating the ohm zero adjustment knob to make the pointer point to the "0" mark on the resistance scale. Every time the magnification gear is changed, it should be set to zero before measurement can be carried out. 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 measured resistance should be disconnected from the circuit and the power should be cut off before the measurement can be carried out.
10. When measuring high voltage and current, it is not allowed to turn the switch knob with power to ensure personal safety.
11. After each measurement is completed, the transfer switch should be placed in the highest AC voltage range or neutral position to avoid misuse and damage to the multimeter by others.
12. If the multimeter is not used for a long time, the battery inside the meter should be removed to prevent corrosion and damage to other components.
