How to use a multimeter: detailed instructions

Any electrician, whether beginner or professional, should be able to use this type of tester, as the multimeter. This device is used for a wide range of measurements in electrical engineering, because thanks to a small box can identify the fault concerning electrical conductors, from any device, and to identify a gap in closed wiring. How to use a multimeter, you will learn from this article.

What is a meter?

Development of instruments began shortly after the advent of electricity, but all the models were very large and were able to measure only one indicator. The first tester that could accommodate a several indicators measuring current, resistance and voltage values ​​has been created by Soviet scientists in 1952. It was named CT-1 and the time experienced multiple enhancements (CT-2, CT-3, TL-4, TC and so on. D.).

How does the multimeter

Each device is equipped with two conductor terminals with black and red, respectively. Further there are from 2 to 4 nests. Red wire is a potential and serves for measuring and black is responsible for the total weight. The mass is carried on the end of a clamp (crocodile) for easy connection to the measured weight of the device. The output of red color are inserted into connectors marked symbols such as: ft, +, V, ampere (A) milliamperes (mA), 10A, 20A.

If you look at the switches, you can adjust the following settings:

• 10B, 50B, 250B, 1000B - a choice of AC and DC voltage (ACV and DCV);
• 5mA, 50mA, 500mA - current;
• H1K, X10, X100 in analog and 200Om, 2K Ohm, 20kOm, 200kOm, 2 MW digital - a multiplication of resistance by a predetermined number of times;

Digital multimeters have additional features acoustical continuity test diodes, temperature sensor, Frequency, Metering capacity capacitorsChecking tracks transistors.

Important! When you want to measure some indicators, but do not know the exact capacity of the device, display the maximum value, dropping them one by one division to adequate numbers of measurement. Thus, you never slept tester.

How to use a multimeter

To begin, you must insert probes to the respective terminals, in black jack labeled COM, and the red connector labeled the V, mA. The third slot is written 10ADC, but it is for the measurement of large currents up to 10A. Next we expose the regulator to ACV or DCV. How to measure the voltage multimeter outlet? ACV should be set to 750, because there is an alternating current.

For more complex measurements are examples below.

How to check the resistance of the multimeter

Permanent resistor - is an essential element of the electrical circuit, which has a constant resistance. Intended for processing linear current-to-voltage and vice versa. The following describes a method for checking a constant resistor.

First it is necessary to set the regulator resistance factor (ohm). If you are not aware of the required value of the experimental device, during a measurement switch factor until the display unit changes to another number.

Now we need to take any permanent resistance to using it to find out how a multimeter to measure the resistance.

Attach test leads of the contacts, and you can check the resistance, which should show 82 Ohm as indicated on the resistor. If the reading is less than more than 10 per cent, the resistor can be thrown out.

Now take a variable resistor, which indicated, for example, 47 ohms.

Check the resistance on the outer contacts, the indicator must correspond to the marking on the resistor body, if it is smaller, it is not certain that the non-operating item. Turn the knob to the left across the resistor and check the left with secondary contacts. Turn to the right and check the middle terminal on the right. Two of the results obtained fold together and if the figure similar to the first, such peremennik more useful on the farm.

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Which multimeter is better to choose for the house.The article explained in detail about what the device is better to choose for the house to meet the requirements of the consumer, the characteristics of future problems and measuring instruments market review.

How to measure the strength of the current multimeter

The current strength is measured only in circuits. AT sockets you can not check the current, because you just create a short circuit. The strength is measured in any electrical circuit AC or DC. Variable nourishes all appliances and comes from a constant batteries.

Putting all modes suitable for the circuit under test, lean probes to the initial node, in turn, prozvanivaya others, identify which node is supplied with a current greater than is calculated on a given node, if any.

Important! For current measurements multimeter do not forget to wear rubber gloves at the time of testing, since the probability of electric shock is very large. And also, do not perform measurements in circuits with high humidity.

How to check the multimeter FET

Such transistors are divided into n and p channel types. Since the n-types are more common, and their check will be described below.

1. How to ring transistor multimeter to resistance? The instrument include measurement of resistance and set a limit on the mark 2K Ohm. Probes need to lean to the source and drain (on the scheme are identified by the letters and, c)

By changing the polarity indicators should be almost equal numbers.

1. Removing the source of the measurement - the shutter. The meter needs to be translated into a continuity diode mode. Red wire connected to the gate (in the figure indicated by the letter h), and the black to the source. Should happen to fall in the open transition to a figure of 650 mV (+/-).

When changing the polarity value should be infinite, that is equal to 1.

1. Now check rates Photo - shutter. All manipulations are carried out as in step 2, only the black probe is connected to the drain. Indicators should be the same.

Changing the polarity similar to step 2.

When you complete all the items and figures are similar to those in the diagram above, we can assume the transistor serviceable.

A method of testing a multimeter capacitors

All capacitors are divided into polar and non-polar. Polar electrolytic capacitors are, all the other modifications - is a non-polar devices.

Polar models feature lies in the way of their rations to the board. Positive contact soldered to plus fees, and minus to minus. Nonpolar can be soldered somehow.

With regard to safety in the polar capacitors, when properly soldered contacts it may explode (concerns Soviet models), in imports are special wrinkles at the top of the housing, which in the case of an explosion just unfold and crush accident.

Speaking about the properties of the capacitor should be noted that he always passes through itself only AC, DC held only a few seconds (not yet charged), then do not miss. To measure capacitance capacitors multimeter must have a capacity of 0.25 microfarads. Otherwise, you'll need a device, such as LC-meter.

To start the measurement, you need to figure out where the capacitor contact minus. It is simple. Manufacturers are applied to the body black tick, which indicates that it is a minus.

Take inspected object, and using any metallic conductor short-circuit contact between them. All discharged capacitor. Now take a meter and set the continuity mode. Lean probes to contacts. The first thing that shows the unit, which is the minimum figure, but in the tester has a battery which gives constant current. It turns out that if you continue to hold the probes on the contacts, the capacitor is charged and the indicators continue to rise indefinitely (1 display).

When the meter is first connected to the device resistance will be zero, or immediately displays unit, then the capacitor does not work.

Note! There is another way to check. It is necessary to charge the capacitor from the power source, which corresponds to its power, and then, using metal to close its contacts. If at the moment of contact will be the spark, the capacitor in working condition.

Methods for performing procalls

There are many examples of the power failure, to identify which need to use a dial. Broken lines may be on both wire feed applianceAnd in the hidden wiring. Identify the gap, you can use a multimeter by making a few simple steps.

1. As an example, will be checked by the cord from the computer monitor, which has three cores.

Exhibiting on the multimeter resistance measurement mode. Then the first probe leans against one of the plug contacts and the second put your turns in each slot connector on the other end. The display multimeter should be a figure of about 2.5 ohms, if the value dostegaet 10 ohms, then this vein contains a gap. The connector, which will show a zero, not a powered contact on the plug.

1. A method of testing the buried wire. Expose on the multimeter function continuity diodes. Now you need to go to the distribution box with automatic rifles. With indicator screwdriver necessary to find a phase including pre all automata. Found tape mark phase.

Further, it is necessary to determine zero. Set the device to check the voltage regulator and to 750V. One probe to the lean phase, and all of the remaining second prozvanivat cableWhile some of them will not give 220 index. Found also mark the wire. In this way, should find all the remaining pairs.

To ping each conductor, it must be disconnected from the power supply (unplug from the machine). Set the multimeter to proring probes and connect with each other. On the display you will see zeros. Disconnecting the probes, a pair of tap conductor. A wire will zero resistance. Prozvoniv remaining pairs of wires, you will be able to determine what kind of line break occurred.

Note! For the full readout, you need a good press the probe tip to check the contact.

Tips and tricks

1. When using an analog (dial) meter, it should be placed on a level surface and avoid any vibrations in the vicinity of the device. Otherwise, its performance will give an error.
2. Never leave the measuring device is turned on, its battery is quickly discharged. If the meter is not provided by the OFF button, then you need to put the position to measure the voltage.
3. Try not to touch the ends of the probe, if they are dirty, there will be uncertainty in the indicators.
4. Before carrying out any action with a multimeter miscalculated every step without haste. Make a mistake, your withdrawal measurements may be left unfinished due to failure of the device.

General conclusion

Now you know how to use a multimeter, but never neglect its settings according to exposing it to the desired performance. With the help of these devices you will easily be able to make friends with electricity. Successful you search for the fault in the mains.