12 points for the use of multimeter
Regarding the precautions for the use of the multimeter, 12 requirements are summarized here. Before use, check whether the pointer of the multimeter is at the zero position. When measuring voltage, do not set the transfer switch to the current or resistance gear. When measuring resistance, you should select the appropriate magnification position. Wait.
12 precautions for the use of multimeters
Precautions for the use of multimeters
1. Before use, check whether the pointer is at the zero position. If it is not at the zero position, adjust the pointer zero adjuster first.
2. Adjust the switch to the corresponding position according to the different properties of the measurand. Pay special attention to when measuring voltage, do not put the switch in the current or resistance gear, otherwise the multimeter will be burned out.
3. When measuring DC current or DC voltage, the red meter rod should be inserted into the jack with the red or "+" symbol, and the other end should be connected to the positive pole of the object to be measured; the black meter rod should be inserted in the black or with the "one" symbol The other end is connected to the negative pole of the measured object.
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 you do not know the size of the measured value in advance, in order to avoid damage to the multimeter due to the selection of the range too small, 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 switch, and pay attention to the relationship between the selected range and the reading on the scale.
7. When measuring resistance, an appropriate magnification position should be selected. Since the scale of the resistance gear is in the reverse scale direction, and the scale is not uniform, the farther to the left, the denser the scale and the worse the measurement accuracy, so the pointer should be deflected at The scale is thin, and the deflection is appropriate near the middle of the scale.
8. Before measuring the resistance, zero adjustment should be performed, the red and black watch rods should be short-circuited, and the ohm zero adjustment knob should be turned at the same time, so that the pointer points to the "0" line on the resistance scale. Each time the magnification gear is changed, it should be zeroed before measurement can be performed. Once the pointer is not adjusted to zero, replace the battery 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, do not turn the switch knob with electricity to ensure personal safety.
11. After each measurement, the transfer switch should be placed at the highest level of AC voltage, or 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.
