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A multimeter is a multifunctional device for calculating various values that will be useful in any home (even if its owner is not an electrician or an experienced repairman). They can measure the mains voltage, find the phase in the outlet, check the health of electrical appliances, and even check the integrity of the wires. In fact, the device is easy to use, the main thing is to figure out the correct installation of the probes and remember the purpose of the ranges of measured values. In the article, we will introduce you to detailed instructions for beginners on how to use a multimeter.
Types of multimeters
There are analog and digital testers. The functionality of both is the same, that is, they can work with all the main parameters. (Of course, now we are not talking about expensive devices that have many additional features.) They differ only in the way the results are calculated: in analog (or pointer) you need to calculate data from the arrow readings (hence, the measurement error is somewhat higher) , in digital, the numbers are simply displayed on the screen. Therefore, today models with an arrow are used less and less, preferring to use their digital counterparts for measurements. Yes, and it is easier to learn how to use the device on a digital device, and it is better if it is a simple model for dummies, for example, Resanta DT 832, DT 181 or DT 830v.
But what the old-style tester looks like and how it works can be seen in the video below, using the example of the Sunwa YX-360 model
Getting to know the tester
The package of any digital multimeter, in addition to the device itself, includes two probes: red and black, as well as instructions in Russian.
The device runs on a conventional 9-volt Krona battery. To learn how to work with it correctly, first of all, you need to understand all its functions, as well as the designations (markings) on the control panel. It contains the following:
- display (measurement results appear on it);
- a switch for selecting functions and ranges, as well as for turning off the device (it can be in the form of a button or a toggle switch);
- three connectors into which probes are inserted (some models may have four connectors).
In many models, for example, the Chinese brand Protech XL830L or Mastech MAS830L, other devices can be found on the front panel, such as a Hold button to hold readings, a transistor test socket, and so on.
The question may immediately arise: why as many as three connectors, if there are only two wires? Everything is simple here: only a black probe is inserted into the connector labeled COM, and only red is inserted into the VΩmA and 10ACD sockets. Which connector to connect the latter to depends on the situation, or rather, on the current strength of the element being measured. If it exceeds 200 mA, need to use socket 10ACD, if it is less than this value, then the connector is used VΩmA. If the model has a fourth slot, it is used for current measurements up to 20 amperes.
Incorrectly connected sockets not only distort the measurement results, but can also cause damage to the device itself, or rather, blow the fuse. That’s why during work this requirement must be taken into account.
Now let’s move on to the main inscriptions on the instrument control panel. They look like this:
- DC voltage is denoted DCV or V with a dash;
- alternating voltage is marked with the abbreviation ACV or V with a wave;
- DCA or straight line A is a DC current calculation;
- And with a wave means measuring the alternating current (not all models have it);
- the sign Ω denotes resistance;
- hfe – this inscription indicates the possibility of checking transistors;
- the inscription OFF means that the device is switched off.
Now, having a general idea of how the tester works, you can proceed directly to the practical part of the training.
Voltage measurement
It is not difficult to measure the voltage with a tester. Let’s start by measuring the constant, for example, in a conventional AA battery.
The sequence of actions will be as follows:
- We connect the red wire to the VΩ jack with positive potential. As we remember, the black wire is inserted only into the COM connector (negative potential).
- We select the measurement limit in the DCV sector, based on the voltage that the measured element itself gives. In an AA battery, this is 1,5 volts, therefore, the toggle switch must be set to a position greater than this value, but at the same time closest to it. This will be 2, 10 or 20 (depending on the instrument used).
- We place the probes on the battery, taking into account the polarity: black – to minus, red – to plus, and look at the results.
The “-” sign that may appear in front of the number indicates a polarity violation. Then the probes on the measured element are simply interchanged.
Attention! Do not touch the bare parts of the device with your hands while working with it, as you may be electrocuted.
The sequence of actions for measuring AC voltage is similar to measuring AC. The only difference is that it is necessary to choose the measurement limit in the ACV sector. To check the voltage in a conventional outlet, the switch is set opposite a number above 220 (it can be 600 or 750).
And since there is no polarity in the change, you don’t have to worry about the correct installation of the wires.
If the result is below 200, then to obtain more accurate readings, you can rearrange the toggle switch to around 200.
Current measurement
Using a multimeter, you can calculate both constant and variable current strength. You need to act like this:
- We determine what kind of current flows through the wires of the measured element – AC or DC. Based on this, we set the switch in section A with a wavy line or in sector A with a straight line, respectively.
- We calculate the approximate value of the current in amperes. This is necessary in order to know which connector is required to connect the red probe.
- We connect the ends of the wires in series with the load and look at the results.
The connection diagram in this case will look like this
If it is impossible to know the value, it is better to start the measurements using the socket with a larger value (10ADC), and then navigate according to the received data. If the value on the screen is smaller, then you can switch the wire to VΩmA.
Attention! It is highly undesirable to measure a current greater than 10 amperes with a tester, since its probes are not designed for large loads. In this case, it is more reliable to use special electrical clamps.
Resistance measurement
This multimeter function is the simplest and most commonly used in everyday life. With its help, you can check home appliances, such as an iron, for a possible failure of the heating element. How to measure resistance correctly? We follow the instructions below.
- We expose the arrow opposite any value in the sector with the sign Ω.
- We check the absence of voltage on the measured element. If this item is ignored, the tester may give incorrect results.
- Let’s look at the result. If 0 or a number with a leading zero is displayed, we reduce the range by one position. If OVER appears, 1 or OL, then on the contrary we increase the values by one position. Thus, it is necessary to bring the readings to an integer, which will be the nominal resistance of the device being measured.
Using a sound call
This feature is also useful in everyday life. It will help determine whether the integrity of the wires is broken, for example, in normal carrying. To use the calling function, you need to do the following:
- We set the switch to ringing mode (indicated in the photo below).
- We attach the probes to the ends of the wire and look at the results.
Attention! There should be no voltage on the measured element.
If you hear a characteristic sound (squeak), and 0 is displayed on the screen, then the electrical circuit is whole.
We have reviewed all the main functions of the multimeter, and also showed how to use them and where they can be used in everyday life. And the basic knowledge gained will definitely come in handy for novice electricians or just radio amateurs.
In conclusion, we suggest you watch some useful videos on what the most popular tester models look like and how to use them.
Ermak DT 182
DT 838
IEC M182