Tester electrical: how to choose and how to use?

At the stage of assembly and subsequent servicing of any electrical devices, it is impossible to do without special tools. One of the most popular among them is the electric tester. It is with its help that checks of the electric circuits are carried out, and also their restoration if necessary. But if for a specialist familiar with electrical engineering the task of choosing this device is easily solved, then for an unprepared person this is a whole problem. In this article we will explain in simple accessible language how to choose an electrical tester, and also point out the existing modifications. In addition, we give a brief description of the methods of work. We remind you that the electric current is dangerous, so without understanding your actions and their consequences, you can get an electric shock. Caution first! Imagine that the electric tester is purchased. The instruction to it is always attached, and it is necessary not only to read it, but also to understand what caused the requirements specified in it.

How to check electrical circuits

The term "electric tester" is applied to the device that checks the wiring diagrams. There are several types of these devices, among which the most famous indicator screwdrivers, specialized voltage indicators, as well as universal multimeters.
They differ from each other in their capabilities and value. What kind of device to give preference, depends on the range of tasks and qualifications of the employee.

Basic functions for small money

The most simple device that allows you to perform an electrical circuit check is the indicator screwdriver. The lower price bracket of this device is about 50 rubles. Outwardly this device not only looks like a well-known tool for twisting screws, but also copes with this task perfectly. However, there are differences. So, in the dielectric handle there is a transparent window, and on the side opposite to the tip, there is a metal contact ring.

As is known, in the electrical circuit the greatest danger is represented by a wire on which voltage-phase is present. A person, touching it, risks getting an electric shock. And it does not matter which phase is on the conductor (A, B or C). But the zero wire and the "earth" are safe. Therefore, when performing work in electrical circuits, it is necessary to first check the conductors. It is for this very simple task that the electric tester, the indicator screwdriver, is designed. Work with it is carried out as follows: holding the device by the handle, one finger needs to be touched to the upper ring, and touch the test area with the probe. If the light illuminates inside, then on this conductor there is a phase.

"Advanced" screwdrivers

There are more complicated modifications of the above device. Outwardly, these are two screwdrivers connected by a wire, one of which has a series of LEDs, each with its designation - 12, 24, 110, 220, 380 V (the order and magnitude in the models are different). The cost starts from 200 rubles.

How can I use an electric tester of this class? The difference between such a complicated version of a screwdriver is the ability to estimate the magnitude of the voltage on each conductor, and not only to register the presence of the phase. To do this, you need to touch one probe of the wire with one probe and the other to the ground. If a series of diodes light up, the latter will indicate the amount of EMF present on the conductor under test. If not, it means that there is no phase on the core. Touching two wires with different phases will result in a "380 V" glow. Note that in the case of like phases, the diodes will remain dark, and this must also be taken into account.

Electric type tester "Contact"

The given group of devices on the possibilities considerably surpasses the above-described "screw-drivers". Although the correct name sounds like a "voltage indicator", when you buy or search for information about them, you can easily find the term "tester". In principle, it really is. For electricians at large enterprises and in electric grid services, voltage indicators for 0.4 kV are issued as the main tool. And it is right. The electric tester "multimeter", which performs the same tasks as the pointer, significantly loses the latter in terms of convenience and reliability. We will describe the class of multimeters below.

Phase Detection Mode

Externally, the voltage indicator resembles a complicated indicator screwdriver: the same two probes, the same row of LEDs, even there is a connecting wire. The difference is that on the main unit there is a metal electrode Ph buried in the body - a thin metal pin, as well as an LED with the same designation. Depending on the design, the latter can be placed either along with the other signaling devices, or separately - from the side opposite to the probes.

The Ph electrode and its LED are intended for the phase conductor detection mode. How to use the electric tester of this design? We give the algorithm for checking the voltage on the conductors:

- the auxiliary unit (there is no indication on it) should be taken in such a way as to exclude the possibility of touching the metal of the probe with a hand. It's usually enough to just take your hand off him;

- The Ph electrode should be touched with a finger. It's absolutely safe. It should be understood that in this case the human body is used as a capacitor, so the hand should not be covered with any dielectric material;

- Holding your finger on the Ph, with the probe of the main unit you need to touch the area under test. If the corresponding LED lights up, then on this conductor there is a phase. The light indication can be accompanied by sound and be intermittent - it depends on the model. If the LEDs are dark, then it is "ground", "zero" or temporarily de-energized area.

It is permissible to use not the main unit, but an auxiliary one, to touch the phase conductor, touching the conductor with its probe. However, this is not recommended, since if the connecting wire blocks are damaged (for example, inside the insulation), then the indication simply does not work. A mistake in determining the phase conductor is a direct danger to life.

Determine the effective voltage value

This device allows, by a few simple steps, to find out what voltage is present on the tested conductor. The order of using the pointer in the mode of determining the EMF value is completely identical to that in the case of a complicated indicator screwdriver.

Chain Integrity

Restoration of electrical circuits is impossible without checking the sites for damage that prevents the passage of current through them. The voltage indicator of the type "Contact" in its capabilities is like a universal electric tester, since it is capable of performing such a check as the latter. For this purpose, a capacitor is installed inside the device, which must be charged before starting the work by touching the probes to "phase-zero" or "phase-phase" for 6-10 seconds. After that, it becomes possible to check the chain for integrity. For example, there is a heating element that does not heat up. In the de-energized condition (with the outgoing lines disconnected), the first probe of the tester must be touched to one terminal of the TEN, and the second to the other. If the spiral is whole, then the diode Test will light up. When you touch the terminal and the housing, you can check the heating element for a "breakdown", etc.

All in one

But the most versatile device is a multifunction electric tester. It can be compared to a road folding knife, which has everything you need. What is an electrical tester? The photo shows that on this device there is a circular switch, rotating which you can select the desired mode of operation. It is important at the same time to read the designations very carefully, since many similar devices burn out because of the haste in the measurements. Taking into account the number of measurements and their limits, it is this tool that is realized at the respective points of sales as an "electric car tester". The cost of these devices starts from 250 rubles.

Multimeters come in two subspecies - analog and digital. The former are equipped with a classical electromagnetic deflection system, and in their design there is a pointing arrow. In many cases, this solution allows for more accurate measurements, but because of the need to recalculate the scale with respect to convenience, the point-to-point multimeters lose significantly in digital. In the latter, instead of the scoreboard with an arrow, the simplest microprocessor is used, which outputs the result to a small display. At the same time, no additional recounting is required. In most cases, it is necessary to purchase a device with such a universal system. There are combined models in which there is both an arrow and a display, but they are more expensive.

In comparison with indicator screwdrivers and voltage indicators , universal testers allow to measure the resistance value, to check transitions in semiconductors of transistors, the current value of current, to determine the "pierced" diodes. In addition, depending on the modification, digital testers allow you to check the ambient temperature with the built-in or additional sensors, the frequency of the electrical circuit, and the capacitance of the capacitors.

How to test the circuit for integrity with a multimeter

In the solutions of the initial price category, there are three holes on the case, to which wires with probes are connected. One connector is necessarily designated as COM - it is used in all cases. To the second, next to which "B, mA, Om" (or English analog) is indicated, a wire is connected, if it is necessary to measure small current (in milliamperes), voltage and resistance. But the third socket is used when it is necessary to determine the high current load (usually this is up to 10A, a constant type of current).

The integrity check is similar to measuring the resistance, with the only difference being that the switch should be turned by a pointer to an item with an appropriate image (for example, a speaker). One wire with the probe must be connected to the COM connector, and the second one to the above socket. Touching the first probe to the beginning of the line being checked, and the second to the end, you can check the integrity of the site. If the display lights up "0", and the sound is heard, the chain is intact. Of course, it is recommended to disconnect all other lines from the checked element and, necessarily, to de-energize it.

How to check battery voltage

No less important is the possibility of determining the potential. For example, the owner of a multimeter should check the voltage on the battery. To do this, one probe connects to the COM, and the second - to the connector "V". The switch is placed in the DCV position with a value of 20 V. After that, it remains at the same time to touch the poles of the battery. The measured value is displayed.

Of course, in this article we can not cover all the options for using the tester. To do this, the owner is recommended to carefully read the instructions and follow it.

How to measure the current

All budget multimeters allow you to determine the current consumed by the load. For such measurements, the device is connected to a circuit break. Having disconnected the power supply of the circuit, it is necessary to fix the first probe on one side of the tested section, and the second one on the other. After switching on, the current will flow through the device, which will display it on the display. For high values it is necessary to use connector "A". And again, in order to avoid electric shock and protect the device from damage, you need to read the instruction.