The multimeter is one of the main tools for professionals in the world of Electrical, as well as clamp meters. Do you know what is the main difference between multimeter and clamp meter? In this article, we will talk about the measurement of electric current using the clamp meter and the multimeter. So come on guys!
Electric current measurement
The electric current is defined by the ordered movement of the electrons, and its unit of measurement is given in amperes (A). The electric current is one of the main electrical quantities and can be continuous or alternating, that is, the electric current can vary its value and direction as a function of time.
There are two different ways to perform the electrical current measurement, which is direct measurement and indirect measurement. The direct measurement of the energy consumed by the load passes entirely through the measuring equipment, as an example the measurement performed by the energy meters of the concessionaire, generally the residential meters.
Another way to directly measure the electrical current is with a multimeter. Direct measurement is only possible when electrons pass through the multimeter’s circuit, so the multimeter is always in series with the circuit to be measured.
This type of measurement should not be done in circuits of residential, building or industrial installations, because this is extremely dangerous for several reasons, for example, the maximum value of electric current that each measuring device is capable of measuring, which is a capacity relatively low and it is necessary to section the cables, being necessary to disconnect the circuit.
The multimeters support measurements up to 10A, some are rarely designed to support the measurement of currents of 20A. The measured values may vary and depend on the time the equipment will be exposed to this measurement.
Another problem with performing direct measurement with the multimeter is that not all circuits can be interrupted to insert the multimeter’s probes, as in most cases it is necessary to cut the cables, interrupting the circuit. And by cutting the cables, later you will need to make amendments, which ends up compromising the efficiency of the installation and creating another heating point in the installation circuit, which can compromise the mechanical resistance of the electrical conductors and several other problems.
The measurement of electric current indirectly is done using current transformers and clamp meters, so the electric current is measured by magnetic comparison, this means that the current does not pass directly through the internal circuit of the measuring device.
The indirect measurement of electric current is indicated for residential, building and industrial installations, as this type of measurement is the safest to make and it is not necessary to section the circuit, avoiding the compromise of the electrical installation.
Another advantage of the clamp meter in relation to the multimeters is that the clamp meter supports the measurement of electrical current values much higher than the multimeters, for longer and more frequently, that is, the clamp meters are manufactured just for current measurement. electrical.
Measurement of electric current in practice
Now we will perform the measurement of the electric current with multimeters and clamp meters in practice, we will see what are the differences between the electric current measurements using a multimeter and then using the clamp meter.
We will use a multimeter to directly measure the electric current with this model, which is capable of withstanding up to 10 A. Before performing the measurement, it is necessary to turn off the circuit, so there is no risk of electric shock. After disconnecting the circuit, we will disconnect one of the power cables, which can be the phase or neutral for connection of the multimeter probes.
It is important to note that in order to measure electrical current, we must pay attention to the terminals that will be inserted into the test leads, because the terminal used to measure electrical current is not the same to carry out the other measurements.
To facilitate the measurement of electric current, we use pressure connectors, and after placing the test leads in the correct terminals, we connect the black test lead at one end of the sectioned conductor and the red test lead at the other end of the sectioned conductor. Then select the alternating current scale and switch on the circuit, so that it is possible to measure the current.
Unlike direct measurement using the multimeter, indirect measurement with clamp meters is simple, practical and quick, without the need to disconnect the circuit. To measure the electric current with clamp meters, just select the alternating electric current scale and wrap one of the conductors with the clamp clamp, thus obtaining the value of the current that passes through this conductor.
It is important to remember that measuring indirectly is the safest way to measure electrical current. Always choose the safest and most practical option possible when it comes to electricity.
Have you ever thought of measuring electrical voltage and electric current at the same time with a single device? Below is the video from the Mundo da Elétrica channel showing the new technologies of the T6-1000 model manufactured by Fluke that measure voltage and current at the same time.