Under what circumstances cannot a multimeter be used or is not recommended?
Multimeter is one of the most important tools for electricians. Because it is simple and practical, it can be said that every electrician has at least one in his hand. It has a huge number. It can measure continuity, voltage, current, and even some electronic components. It seems to be omnipotent. The ability is particularly strong, which is also the origin of the name of the multimeter.
We often say that a multimeter can do this or that, and we always keep it with us every time we repair it. But have we ever thought that there are situations when a multimeter cannot be used or cannot be used?
Today, let’s talk about the shortcomings of multimeters. The first is current. Multimeters can actually measure current. However, when measuring current, they must be connected in series in the circuit, otherwise they cannot be used. Generally speaking, you want to connect the multimeter in series in the circuit to measure. , it is very unsafe when the current is large. On the other hand, sometimes the circuit has to be disassembled and connected in series. Therefore, the multimeter is not very commonly used and not very practical when measuring current!
Secondly, it is to measure the resistance to the ground and the insulation resistance of the motor cable. Because the power source used by the multimeter is a battery, the voltage is low, and the resistance of the insulation resistance measured to the ground, cables and motors is relatively large, and it is difficult to measure it with a multimeter under normal circumstances. Even if the effective resistance is measured, the error is generally large, or even the wrong value, which has no actual reference value and is sometimes misleading. Therefore, it is not recommended to use a multimeter in this case.
Another situation is that the multimeter cannot be used, which is the battery capacity. People often say that my battery car has just been charged and runs out of power after driving for a while. Is the battery broken? This so-called bad battery actually means that the battery capacity is reduced. A multipurpose surface cannot be used for this type of problem!
