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 repairman with extensive experience). They can measure the mains voltage, find the phase in the outlet, check the health of electrical appliances and even conduct a wire integrity check. 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 the multimeter.
Types of Multimeters
There are analog and digital testers. The functionality is the same for both, that is, they can work with all the main parameters. (Of course, we are not talking about expensive devices, which have many additional features.) They differ only in the method of calculating the results: in the analog (or arrow) you need to calculate the data from the arrow (therefore, the error in the measurements 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. And learning to use the device is easier 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 here is what the old-style tester looks like and how it works, you can see the video below, on the example of the Sunwa YX-360 model
Meet the tester
In addition to the device itself, two digital probes are included in the package of any digital multimeter: red and black, as well as instructions in Russian.
The device runs on a regular 9-volt Crohn battery. In order to learn how to work with him correctly, first of all, you need to deal with all its functions, as well as the signs (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 (may be in the form of a button or toggle switch);
- three connectors into which the probes are inserted (there may be four on some models of 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 the Hold button to hold readings, the socket for checking transistors, and more.
The question may immediately arise: why the whole three connectors, if there are only two wires? Everything is simple here: only a black colored 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 measured element. If it exceeds 200 mA, you need to use the 10ACD socket, if it is less than this value, then the VΩmA connector is used. If the model has a fourth socket, then it is used to measure current up to 20 amperes.
Incorrectly connected sockets not only distort the measurement results, but can also cause a breakdown of the device itself, or rather, a fuse blown. Therefore, during operation, 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 indicated by DCV or V with a straight line;
- AC voltage is abbreviated ACV or V with wave;
- DCA or A with a straight line is a calculation of direct current;
- And with a wave, it indicates AC metering (not all models have it);
- the sign of Ω denotes resistance;
- hfe - this inscription indicates the possibility of checking transistors;
- OFF indicates that the appliance is turned off.
Now, having a general idea of how the tester works, you can go directly to the practical part of training.
Voltage measurement
It is not difficult to measure the voltage with a tester. Let's start by measuring the constant, for example, in an ordinary AA finger-type 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 gives itself. In a 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. It will be 2, 10 or 20 (depending on the device used).
- We place the probes on the battery, taking into account the polarity: black - to the minus, red - to the plus, and look at the results.
The sign “-“, which may appear in front of the number, indicates a violation of polarity. Then the probes on the measured element simply change places.
Attention! You can’t touch your hands to the exposed parts of the device while working with it, as you may be shocked.
The procedure for measuring AC voltage is similar to measuring AC. The only difference is that it is necessary to choose a measurement limit in the ACV sector. To check the voltage in a conventional outlet, the switch is set opposite the number above 220 (this can be 600 or 750).
And since there is no polarity in the change, then you do not 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. You need to act like this:
- We determine which current is flowing through the wires of the measured element - alternating or constant. 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 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 find out the value, it is better to start measuring using the socket with a higher 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 of more than 10 amperes with a tester, since its probes are not designed for heavy loads. In this case, it is more reliable to use special electrical measuring pincers.
Resistance measurement
This multimeter function is the most simple and often 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? Follow the instructions below.
- Set 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.
- We look at the result. If 0 or a number with a zero in front is displayed, reduce the range by one position. If OVER, 1 or OL appears, then vice versa 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 measured device.
Using sound tones
This feature is also useful in everyday life. It will help determine if the integrity of the wires is violated, for example in a normal carrying. To use the dialing function, you need to do this:
- We set the switch to dialing mode (indicated in the photo below).
- We attach the probes to the ends of the wire and see 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 electric circuit is intact.
We examined 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 acquired basic knowledge will certainly be useful to beginner electricians or just hams.
In conclusion, we suggest you watch some useful videos on how the most popular tester models look and how to use them.
Ermak DT 182
Dt 838
IEK M182