A multimeter is a device with which a voltage value, current strength, resistance are measured, wire “wiretap” is performed. That is, this device is quite in demand. Moreover, as practice shows, it is quite popular not only in industry, but also in everyday life.
But before proceeding with the necessary measurements, it should be noted that the multimeter is not a completely harmless device. With improper use, you can not only easily disable it, but also cause serious harm to your health. This is especially true in cases where you need to take measurements at high voltage or high amperage. You can not only immediately burn a multimeter, but also get a serious electrical injury.
That is why, before you start using the multimeter, you need to practice using power supplies with low current indicators, such as batteries. Also, do not neglect the instructions for the device.
Varieties of multimeters
To begin with, you should know that multimeters are digital and analog (pointer, even among electricians they are known as a "workshop"). The second has been known to electricians for a long time, but it is quite difficult to use them without special knowledge and practice.
- you need to be able to understand the scales of the device, of which there are several on the dial multimeter;
- the device should be kept in such a position that the arrow on it will not “walk” on the scale.
That is why, if there is such an opportunity, it is better to use a digital multimeter. We will also consider examples using a digital device, since it is quite difficult to learn how to work with analog multimeters on your own.
There are a lot of varieties of digital multimeters, but the principle of their operation is similar to each other - the difference is only in the number of functions of the device. Accordingly, the price also depends on the functionality of the multimeter, so before you buy it, decide what you need it for.
The multimeter consists of:
- the device itself;
- two probes (black and red);
- power supply (9V battery "Krona").
So, what are the features of using this measuring device and how to check amperes with a multimeter?
Instruction manual
In order to measure the current strength in the circuit, it is necessary to connect a device to it in series. In this case, on the multimeter itself, it is necessary to insert the red probe into the socket on the device with the inscription mA, and the black one into com. Serial connection means that the circuit must be broken and each probe is connected to a different wire, i.e. the device must be connected between two power sources. But since you measure the strength of the current, and it is simply impossible to do this in power sources, you need to turn on some device, for example, an ordinary light bulb, placing it in the circuit immediately after the power source.
If you measure the strength of alternating current, then the maximum value of alternating current is set on the device (A ~ icon - note that it is very similar to the DC icon (A-), so be careful). And only after that you can start measuring.
Before checking the amperes with a multimeter, make sure that the strength of the measured current will not be too high, since such measurements may be unsafe due to the small cross-section of the probe wires. The latter may not withstand high loads. Experts recommend taking measurements at a current of more than 10 A with electrical measuring clamps.
Battery check with a multimeter
The check must be carried out only under load. Check how many amperes are in the battery with a multimeter, only with using the internal capacity of the battery is impossible because of its small size - the obtained indicators will not display the true numbers.
The tester can measure not only the operating current, but also the leakage current of the battery. Before checking with a multimeter how many amperes is the leakage current, it must be remembered that it can reach several amperes. Therefore, it is necessary to set the measurement limits on the device correctly, preferably up to 10 A.
In practice, before checking the amps on the battery with a multimeter, you should fold the plus wire from the battery terminal and include a measuring device in the gap. After that you need:
- select a mode on the multimeter for measuring current strength;
- fix the wires with “crocodiles” and pull out the fuses that are responsible for the electronic module in the car.
With some practice, you will not only know how to check the amperes with a multimeter, but you can also easily detect the causes of the leak without contacting a service center.
Charger Check
Before answering the question: "How to check the amperes with a multimeter on the charger?", You need to know that you can measure, in principle, any charge. It can be from phones, tablets, memory for a car battery, etc.
Phone charger
Such measurements are most often necessary when it is necessary to identify the cause of the failure of the memory. It should be noted that the current strength on the chargers of phones, tablets, etc. differs insignificantly and is usually indicated on the charging sticker or marking itself. But if for some reason there is no such inscription, then you can check this indicator with a multimeter.
The principle of measuring the current strength in the charger can differ only in that, due to the small size of the contacts on the connector, it is quite difficult to connect the multimeter probes to them. For this, it is necessary to carefully insert ordinary steel sewing needles into the contacts and connect the multimeter probes to them already. If this does not work out, the only way out is to open the charger case in order to connect the probes directly to the terminals of the charger in the place where the ends of the electric cord are soldered.
Car Battery Charger
Before talking about how to check amperes with a multimeter on the charger for a car battery, you need to know what it is for.
The optimal value of the charging current of such a charger is 10% of the battery capacity of the car. A large value will allow you to charge the battery faster, but will negatively affect the battery itself and significantly reduce the time it is used.
When purchasing such a memory in the store, all parameters are written on the charger itself. But such a charge, with minimal knowledge, can be done independently. In this case, you will need a multimeter. Also, this measuring device is useful if the charger fails.
It should be said that when measuring the current strength of any chargers, any load (for example, an ordinary light bulb) must be included in the circuit. Also, do not forget that often the charger generates direct current, so the multimeter's handle should be set to the correct position (A-).
Power supply check
How to check the amperes with a multimeter on the power supply? This is also done to break with the obligatory use of the load. The principle itself is not much different from checking other sources. It should only be noted that PSUs have a rather high power, therefore, measurements should be carried out quickly, without allowing heating of the wires of the multimeter probes.
As we can see, a multimeter can be very useful in everyday life and in demand in completely different areas, so getting the most minimal knowledge on its use will not be superfluous at all.