One of the main parameters in electrical engineering is the current strength, which is an electric current in a certain amount passing through a conductor of a certain section. This value is of great importance for the normal operation of electrical systems, so the question of how to measure the current strength with a multimeter often becomes relevant. This procedure is necessary in order to know exactly about a particular current level set for a particular circuit. The multimeter is the main instrument with which measurements are taken.

How to measure the current in the socket with a multimeter

Before starting measurements, first of all, measuring probes are connected to the device. Each of them has its own color - black and red. The black probe is usually common, zero or negative, so it is connected to the bottom connector, marked with COM symbols. Another red probe is connected to the middle connector during measurements. There is a connector located on the top of the multimeter that plugs into the red test lead when measuring AC current up to 10 amps.

After connecting the probes, the desired operating mode is selected by turning the round switch and setting it to the desired position. If the value of the measured parameter is known in advance, then the set measurement limit should slightly exceed it. This measure allows you to protect the multimeter from burnout. In the event that there is no information about the possible readings of the device, the maximum possible measurement limit is set.

When measuring voltage, the device is connected to the circuit in parallel, and for measuring current strength - in series. Measurement of semiconductors or resistance parameters is performed with the power off in this circuit. can also be measured with a multimeter. To do this, the switch must be moved to the ACV position at around 750 volts, and then measure. In the same way, a measurement is performed in a network with a voltage of 380V. The current in the outlet is measured by setting the device to the AC current measurement mode.

How to measure transformer current with a multimeter

The flow of electric current in the transformer is carried out exclusively in a closed circuit. In order to measure the current, you must first connect some load, and then a multimeter is connected in series with it in the circuit. In this case, the switch is also set to AC measurement mode. The red wire is connected to a separate output.

At the preparatory stage, you need to do the following:

• The probe with a black wire is installed in the corresponding black socket, and the probe with the red wire is installed in the red socket, where there is an “A” designation, that is, amperes.
• The toggle switch switches to the desired position: for measurements of alternating current - AC, direct current - DC.
• The measurement limit is set so that it is higher than the expected current level in the circuit. This will help keep the device from burning out.

After preparation, you can proceed to direct measurements. To this end, the multimeter must be connected in series to the break in the electrical circuit between the transformer and the load. The amount of current passing through the device will be displayed on the display of the multimeter. In the absence of a load, a limiting resistance can be included in the circuit - an ordinary light bulb or a resistor.

If the display does not show the current value, then the measurement limit is incorrectly selected and it must be reduced by one position. If there is no result, the procedure must be repeated and continue to do this until a value appears on the display.

How to measure battery current with a multimeter

Despite the external similarity, all batteries have different parameters and technical characteristics. In this regard, quite often there is a need to check the performance of these elements, in particular, to measure the current strength.

The main testing method concerns new batteries, allowing you to determine their performance at the time of purchase. For measurements, the multimeter is set to the position corresponding to direct current. Next, the procedure will be as follows:

• The multimeter must be set to the maximum measurement range.
• The probes of the multimeter are applied to the contacts of the battery.
• After the increase in current on the screen stops, after about 1-2 seconds, the probes are removed.

The normal amount of current in a new battery is usually 4 to 6 amps. If the indicators are from 3 to 3.9A, this indicates a decrease in the battery life. Therefore, it can only be used in devices with reduced power. At lower rates, batteries can only be used in very weak devices or not used at all.

How to measure DC current with a multimeter

The measurement of direct current is carried out in the same way as when measuring batteries. It's just that in this case the multimeter is also used to check more powerful devices. First of all, these are either rectifiers used in industry and in everyday life.

For measurements with a multimeter, any two points are selected, between which the measuring device is connected in series. The connection must be made with the obligatory observance of polarity. If the multimeter is connected incorrectly, the display will show a value with a minus sign.

In the event that the value of the estimated current strength is greater than the uppermost measurement limit, it is necessary to set the switch to the “10A” position. At the same time, the measuring probe moves from the “V ΩmA” socket to the “10A” socket.

How to measure AC current with a multimeter

Before starting measurements, it is necessary to determine exactly what current will be measured - AC or DC. After that, the multimeter switch is set to the desired position. Next, you need to set the approximate force in this circuit in order to connect the measuring probe to the appropriate connector. If the current is expected to be up to 200mA, the probe is connected to the “V ΩmA” socket, and if the current is more than 200mA, to the “10A” socket.

Sometimes it happens that there is no information about the current strength at all. Therefore, measurements should be started from the maximum value. If a lower current appears on the display, then the plug needs to be moved to another connector. In the case when the current is again less than required, the plug is again rearranged. If necessary, the regulator knob should be set to a lower current level. Before starting measurements, you need to carefully study all the symbols printed on the multimeter and in the future select only the desired symbolism. All measurements must be carried out from maximum to minimum values, this is a mandatory requirement when working with a multimeter.