How to use a multimeter for "dummies"? How to call a wire with a multimeter

A multimeter is a tool for measuring electricity, the same as a ruler for determining distance, a stopwatch for time or a weighing scale. Its difference lies in the fact that it is multifunctional, that is, it can measure different quantities. Most multimeters have a switch that allows you to select what you need to measure.

What does the device measure?

Multimeters are able to measure current, resistance and voltage, as well as monitor the continuity of the circuit, giving a signal in the event that two things are electrically connected. This is useful, for example, when installing wiring and twisting or soldering wires. A beep indicates that there is a connection, and nothing disconnected. The device can also be used to ensure that there is no electrical connection between the two conductors. This will help to detect a short circuit.

Multimeters can test diodes. They are similar to a one-way valve that passes current only one way. Different manufacturers may have different implementation. When working with diodes, if there is no confidence in how it is included in the circuit, or in its serviceability, the possibility of verification will be very useful. If the tester-multimeter has this function, in order to find out exactly how it works, read the instruction.

More expensive devices can, for example, check the performance and measure the characteristics of capacitors and transistors.

The Aces of Electrical Engineering

Information on how to use a multimeter, for "dummies." Resistance, voltage, current are parameters that can be measured in units denoted by symbols. For example, the distance is expressed in meters or by the symbol m. In electronics this is:

1. The voltage expresses the strength of the electrons being pushed along the chain. A larger value is equivalent to applying more effort. Measured in volts (V).
2. The current strength expresses how many electrons move along the chain. A higher value corresponds to a higher electricity consumption. Measured by amperes (A).
3. Resistance expresses how difficult it is for electrons to pass through something. The higher it is, the more difficult it is to pass the current. It is expressed in ohms (Ω, omega).

The symbol denoting the unit of measure differs from the variable in the equation. For example, Ohm's law is expressed as:

• U = IR, where I - current, U - voltage and R - resistance.

Volts, Amperes and Ohms are denoted by V, A, Ω.

To understand how to use a multimeter, for "dummies" it will be useful to bring to the aid of a simple analogy. The current is similar to the movement of water in the pipe. Its higher flow means more current. The pressure that creates the movement of water is tension; A higher pressure "pushes" the water more, increasing the current. Resistance is like an obstacle in a pipe. For example, through a pipe filled with garbage, water will flow with difficulty. Its resistance will be greater than that of a pipe free from obstructions.

Alternating and direct current

One more information that must be learned before using the multimeter. For "dummies" it will be interesting to learn that a constant current moves in one direction. Its source can be, for example, a conventional battery. Different multimeters differently designate a constant voltage and current. Typically, this is DCV and DCA, or a straight line over V and A.

The alternating current changes the direction of motion many times per second. In a home network, this happens 50 times (in the US - 60 times per second). In different multimeters, the alternating voltage and current are indicated in their own way. Typically, ACV and ACA, or a wavy line (~) near or above V and A.

Parallel and serial connection

When using a multimeter, you need to determine the order of its connection, which depends on what you want to determine. In a series circuit, the current flowing through each of its elements is the same. Thus, for its measurement it is necessary to connect the device in series. In a parallel circuit, each element has the same voltage. Therefore, to measure it, the multimeter must be connected in parallel.

What do the symbols on the front panel mean?

Another information you need to know before using a multimeter. For "dummies" it will be difficult to understand the many symbols on its front panel, especially if there are no inscriptions. No worries. They are represented by units of measurement V, A, Ω.

Most multimeters use metric consoles that behave in relation to units of electricity measurement in the same way as with distance and mass. The meter, for example, is a unit of distance, a kilometer is 1000 m, and a millimeter is 1/1000 m. The same applies to kilograms, grams and milligrams of mass. The most common metric consoles used in multimeters:

• Μ (micro) = 10 ^-6 ;
• M (milli) = 10 ^-3 ;
• K (kilo) = 10 ³ ;
• M (mega) = 10 ⁶ .

These metric consoles are used for Amp, Volt and Ohms. For example, 200kΩ is two hundred kilograms, which corresponds to 200,000 ohms.

Setting limits

Some multimeters are automatically configured, others require manual setting of the measuring range. In the latter case, you should always choose a range slightly above the expected value. It's like a ruler and a tape measure. If you want to measure something that is 60 cm in length, then the 50-centimeter ruler will be too short, and you'll have to use a tape measure.

The same applies to the multimeter. Suppose you want to measure the battery voltage AA, the value of which is expected to be 1.5 V. There are options for 200 mV, 2 V, 20 V, 200 V, 600 V. 200 mV is too small, the next higher value of 2 V should be selected. The options are too large, their choice would lead to a loss of accuracy (this is how to use a 5-meter tape measure with centimeter divisions without millimeters).

What do the other symbols mean?

The following symbols are often used in measuring instruments:

1. Wavy line. It is located near the symbols V, A together with metric prefixes. Indicates the variability of the measured quantity.
2. Solid line, dashed. Located near or above V or A and indicates a constant voltage or current.
3. A series of parallel arcs. Used for checking the electrical connection. How to call a wire with a multimeter is described below.
4. AC, DC. Instead of lines, the abbreviated name AC (AC) and DC (DC) current can be used.
5. A triangle with lines drawn through it. Used for testing diodes.

Selection options

What should be a good multimeter? Feedback from users allows us to distinguish the following features, which should pay attention in the first place:

• Wires should not break after a few uses;
• The presence of automatic shutdown;
• Convenient location of buttons and connectors;
• Automatic selection of the measuring range;
• Sufficient LCD screen size;
• accuracy class;
• Ranges of measurements.

Multimeter: Wiring instructions

Measuring instruments are sold together with red and black wires with probes. One end is connected to the multimeter, and the probe is used to test the circuit. The red test lead is used for positive, and black is used for negative values.

Although the wires are only 2, there are more places to connect them, which can cause confusion. The method of connecting the wire depends on the measurement subject and the model, so for clarification, refer to the user manual.

Most multimeters are protected from a large current by a fuse that melts and breaks the circuit. This will prevent the device from malfunctioning.

If you attach the test leads to the element or the section of the circuit, the digital display will show the result. The switch sets the voltage, current or resistance, as well as the measurement limits.

Determining the integrity of a connection

How to call a wire with a multimeter? For this you need:

• Insert the red wire into the connector Ω, and the black wire into the COM;
• Set the switch to the sound symbol in the form of parallel arcs;
• Connect test leads to test points;
• The device will beep if the connection between the two probes exists (i.e., the resistance is close to zero) and will remain silent when it is not.

Multimeter: instruction for measuring resistance

The problem with resistors is that manufacturers want users to remember the color that encodes their characteristics. Here's how to properly use a multimeter to determine the resistance:

• Insert the red test lead into the Ω socket, and the black probe into the COM;
• Connect the test leads to the resistance contacts;
• Select the required measurement limit;
• Read the value.

If your indicator lights 1, then the limit is too small. It is necessary to set the switch to a higher value until the correct reading is obtained. If the value is close to zero, then the limit is too high. It must be reduced to obtain a real indication. If the value is still 0 at the smallest limit, then the measured resistance has a zero value.

Determination of voltage

To measure a DC voltage, you need:

• Insert the red test lead into the V socket, and the black probe into the COM;
• Connect the red test lead to the positive side of the battery or circuit, and black - with negative or ground;
• Set the limit switch to the position of measuring the DC voltage of the expected range;
• Read the device.

On the device next to the sockets, the maximum permissible current and voltage are indicated. If these values are not observed, the multimeter circuit may be damaged.

To determine the alternating voltage, you must select the appropriate limit. In this case, the order of connecting probes does not matter.

Current measurement

• Insert the black wire into the COM connector.
• Insert the red wire into the connector that corresponds to the intended measurement range. The multimeter 832, for example, has connectors for currents up to 200 mA and 20 A.
• Set the limit switch to the DC measurement position of the intended range.
• Read the testimony.

The requirements for limiting the test current indicated on the device must be observed. Otherwise, the fuse will trip if it is set for this measuring range or the multimeter circuit may be damaged.