Which multimeter is more suitable for maintenance use, MF30 or MF50
Precautions for using a multimeter
(1) Before using a multimeter, it is necessary to perform a "mechanical zero adjustment", which means that when there is no measured electricity, the multimeter pointer should be positioned at zero voltage or zero current.
(2) During the use of a multimeter, do not touch the metal part of the probe with your hands. This ensures accurate measurement and personal safety.
(3) When measuring a certain amount of electricity, it is not advisable to shift gears simultaneously, especially when measuring high voltage or high current. Otherwise, it may cause damage to the multimeter. If you need to shift gears, you should first disconnect the probe and shift gears before taking measurements.
(4) When using a multimeter, it must be placed horizontally to avoid errors. At the same time, attention should also be paid to avoiding the influence of external magnetic fields on the multimeter.
(5) After using the multimeter, the transfer switch should be placed at the maximum AC voltage position. If not in use for a long time, the battery inside the multimeter should also be removed to prevent the battery from corroding other components inside the meter.
The use of Ohm gear
1、 Choose the appropriate magnification. When measuring resistance with an ohmmeter, an appropriate magnification should be selected so that the pointer indicates near the median value. It is best not to use the left third of the scale, as this part of the scale is densely packed.
2、 Adjust to zero before use.
3、 Cannot measure with electricity.
4、 The measured resistance cannot have parallel branches.
5、 When measuring the equivalent resistance of polar components such as transistors and electrolytic capacitors, attention must be paid to the polarity of the two pens.
6、 When measuring the equivalent resistance of nonlinear components with different magnification ohm gears of a multimeter, the measured resistance values are different. This is because the median resistance and full scale current of each gear are different. In mechanical meters, the smaller the magnification, the smaller the measured resistance value.
When measuring DC with a multimeter
1、 Perform mechanical zero adjustment.
2、 Select the appropriate range gear.
3、 When measuring current using a multimeter's current range, the multimeter should be connected in series in the tested circuit, because only serial connection can make the current flowing through the ammeter equal to the measured branch current. When measuring, the measured branch should be disconnected and the red and black probes of the multimeter should be connected in series between the two disconnected points. Special attention should be paid to the fact that the ammeter cannot be connected in parallel to the tested circuit, as this is very dangerous and can easily cause the multimeter to burn out.
4、 Pay attention to the polarity of the measured electric quantity.
5、 Correct use of scales and readings.
6、 When selecting the 2.5A range using direct current, the red probe of the multimeter should be inserted into the 2.5A measurement socket, and the range switch can be placed on any range of the direct current range.
7、 If the measured DC current is greater than 2.5A, the 2.5A gear can be extended to 5A gear. The method is very simple. The user can connect a 0.24 ohm resistor between the "2.5A" socket and the black lead socket, so that this gear becomes a 5A current gear. The 0.24A resistor to be connected should be selected with a wire wound resistor of over 2W. If the power is too low, it will burn out.
