Without a doubt the multimeter is the most important tool for the electrician, being essential in practically all his activities, but it is still common to have several doubts regarding the correct way to use a multimeter. Thinking about it, we decided to teach some tips on how to use the multimeter correctly, in addition to warning about the main mistakes that are made with the multimeters, because a simple mistake can be fatal. Come on, guys!
Care before using the multimeter
We must warn about the dangers when handling a multimeter, as this equipment will be in direct contact with live parts of a circuit or very close to live parts, and any problem with the equipment can put the person’s life at risk.
Lack of knowledge
We know that there are many enthusiasts and lovers of electricity, but not everyone can handle a multimeter, it is necessary to have basic knowledge about the main magnitudes of electricity, in addition to understanding how each of them behaves in a circuit and actually know the equipment.
Failure to adhere to these criteria is the most serious of all errors, so, before starting a measurement, research and study about the multimeter and the electrical quantities .
Using multimeters from unknown brands that have no certification, category or origin is a big mistake, so the importance of knowing the multimeter you are about to use. Do not worry about these details, no matter how much the multimeter’s price influences when buying, remember, your life is worth more!
Pay attention to the multimeter category, because when we use multimeters of smaller categories for certain measurements, we can damage the equipment, in addition to the risk for those who are performing these measurements, by not offering adequate protection against surges and transients in the network.
Probe tips and scales
Errors when selecting the test lead terminals or the multimeter scales are serious errors, because in addition to damaging the measuring equipment, the risk of an accident is very high. So stay tuned where the test leads’ terminals are fitted and see if the scale selection is correct.
How to use multimeter
When connecting the test leads to the multimeter terminals, be aware that the chosen terminal must be in accordance with the measurements you want to make, in addition it is important to understand that the terminals of the multimeter may vary according to the type of multimeter.
To understand how to fit the probes to the correct terminals, we will use the multimeter in the image below as an example. Therefore, if we want to measure a current of up to 10A we must connect the probe to the first terminal. In the case of very low current, of milli or micro ampere, the second terminal must be used and for the other measurements such as voltage, resistance and continuity, the fourth terminal must be used.
We are subject to making mistakes during measurements, so before making any measurement it is necessary to choose the correct scale, be aware if the scale is in accordance with the measurement to be performed. For better measurement accuracy, some multimeter models have a wide range of selection, such as 200mV, 2V, 20V, 200V, 2mA, 20mA, 200mA and 20A.
If you try to measure a voltage of 220V on the 200mV scale, your multimeter can be damaged and reading the numbers can lead to an error, causing accidents. A very common mistake in these cases is to think that there is no voltage in a circuit, when in fact there is voltage.
If measuring voltage in an installation, always place the multimeter on the highest scale, to ensure its safety and the integrity of the device, be sure to check if the circuit is alternating or direct current.
Test the multimeter
Before starting your task, always check how the equipment to be used is working, testing it on a known voltage source.
Measuring electrical current with a multimeter and not with a clamp meter is one of the most dangerous measurements, moreover we do not recommend this practice, as the risks are many, therefore when making electrical current measurements in a switchboard or any other circuit an installation use a clamp meter, as they are made for this type of measurement.
The video below complements this article, showing details on how to use the multimeters correctly and mainly, how not to use a multimeter, it is worth checking out.