In order to successfully buy a wire, before buying it is necessary measure wire diameter Otherwise, you may become a victim of fraud. You will also have to measure the cross section of the wire if you add a new electrical point to the old wiring, since there may not be letter markings on it. The information below will help you choose the right technique. wire diameter measurement and use it effectively in practice.
The frequencies used here do an interesting thing for the importance of the conductor, which requires an understanding of 3D thinking. What this means for the wire is that the increase in size is no longer as significant as on low frequencies, since the increase in the surface area of the wire is proportional to the diameter, not the square of the diameter.
But if we look at the skin effect, the picture changes. The cross-sectional area is practically irrelevant, because the "skin depth" is worth almost nothing. Instead of cross-sectional area, the loss of resistance will be inversely proportional to the amount of copper that the signal actually passes through, i.e. it will be inversely proportional to the surface area of the cable, or, in cross-sectional terms, to its perimeter.
At the same time, you will immediately have a question: “What is the point of a company to spoil its reputation?” There may be several explanations for this: But the thing is that even having made the correct calculations for the wire cross-section, you can still run into a problem, despite the fact that you buy wire with suitable diameter. An accident can occur due to the fact that the conductor section will be indicated on the wire marking, which does not correspond to the actual one. This may happen as a result of the fact that the manufacturing plant saved on the material, or the company that produces this product did not comply with all the characteristics of the product. Also on the shelves you can find wires on which there is no marking at all, which initially makes one doubt their quality.
Now any drag reduction is good; the point here is simply to show that he is not as good as one might expect. These parameters are generally difficult to control and have nothing to do with a wire gauge, except that it is sometimes easier to control tolerances larger than in a smaller cable. A cable with excellent return loss and skew can easily outperform a larger cable at a distance.
A wired sensor can be a significant factor in cable quality; but since it is very important for some applications such as speaker wiring, only moderately significant for others such as analog and digital video, and practically meaningless for others, it is important to understand the requirements of the application before judging the quality of a cable based on a wire gauge. When manufacturers are unable to publish detailed product specifications, it can be a mistake to base estimates of relative quality on any limited specification, be it a wire gauge or something else.
1. In order to save money. For example, the factory made wire diameter less than 2 mm. sq. with a 2.5 mm core, which made it possible to win several kilograms of metal on one linear meter, not to mention profit in mass production.
2. As a result of great competition, the company reduces the price of electrical wiring, trying to lure the majority of consumers to itself. Naturally, this happens due to wire diameter reduction which cannot be determined with the naked eye.
How does this tool work?
Didn't find an answer? Then send us your question, we will be happy to answer you! In our applications, the videos simply and vividly show how to use the tools correctly.
What is being filmed
In the case of stripping, the insulation of the electrical conductor is stripped to establish a connection for the electrical connection.Basically, a pair of two pliers are installed around the axis of the parts, which are designed on one side as a handle, on the other side as a working head. Removable pliers pull knives that cut through the insulation when the handles are closed and then remove the conductor of the wire. One differential between tongs with manual adjustment on wire cross-section, automatically adjusts tongs and those with one or more pairs of knives for well-defined cross-sections.
Both the first and second options take place in the sales market, so you better play it safe and make accurate calculations yourself, which will be discussed further.
Three main ways to determine the diameter of the wire.
There are several ways, but each of them is based on determination of diameters veins with subsequent calculations of the final results.
Why do you need coaxial cables and how to remove them?
They are in the converted true metric value, usually slightly below the mm2 we set for which our tools are designed. Cables consist of a flexible or solid conductor that is insulated from a thicker, more stable plastic layer called the dielectric. A metal mesh or aluminum foil surrounds the insulation to keep external electrical or magnetic influences away from the conductor and to avoid interference. The outer shell surrounds the screen and protects it from environmental influences.
Method one. With the help of appliances. Today, there are a number of devices that help measure wire diameter or strands of wire. This is a micrometer and caliper, which are both mechanical and electronic (see below).
This option is primarily suitable for professional electricians who are constantly involved in the installation of electrical wiring. The most accurate results can be obtained with a caliper. This technique has the advantage that it is possible measure wire diameter even on a section of a working line, for example, in a socket.
Depending on the type of cable, there are different versions with a set of knives next to the body or two sets of knives at both ends. If the lock, which is usually installed on the longitudinal side, is released, the semi-circles open under spring pressure and the cable can be inserted. After closing the sheaths, the cable sheath is cut using rotary motion to remove it. Slim shape tool makes it easy to remove the outer shell inside wall or outlet sockets.
Is splitting the same as deleting?
De-stripping is the removal of the outer sheath of the cable. Circular or flat cables consist of a number of insulated conductors that are surrounded by a cable sheath - generally thicker than the plastic layer. To be able to use single conductors for electrical connection jacket must be removed. This process is called de-mantling.
After you have measured wire diameter, it is necessary to carry out calculations according to the following formula:
It must be remembered that the number "Pi" is 3.14, respectively, if we divide the number "Pi" by 4, we can simplify the formula and reduce the calculation to multiplying 0.785 by the diameter squared.
Numerous manufacturing units in the electronics industry must be protected from electrostatic effects. Among other things, it requires the use of tools for which a special plastic generated static energy can be obtained.
How is fine wire different from solid, stranded, or thin wire?
Leader Class 1 - Massive Leader
One round, round cable. Consists of fully wired, usually copper. Often surrounded by an insulating layer of plastic. Conductor class 2 - stranded conductor. A conductor consists of several individual conductors located inside each other. It is often used with leads with large cross-sections.Method two. We use a line. If you decide not to spend money on the device, which is logical in this situation, then you can use a simple proven method to measure the cross section of a wire or wire ?. You will need a simple pencil, ruler and wire. Strip the core from the insulation, wind it tightly onto a pencil, and then measure the total length of the winding with a ruler (as shown in the figure).
Conductor class 5 - Conductive conductor
The structure of the line consists of several finely spaced thin threads, which can also be twisted in some cases. This makes the conductor flexible. It is often used, for example, in household appliances.
Conductor class 6 - extra fine conductor
The cable assembly consists of a plurality of threads arranged around each other and partially also twisted. Sketch Stair classes.What is the difference between cable and cable?
The Jokari knife is a rope knife made by the inventor of cable knives, Jokari. This is a modern cable knife, consisting of a plastic handle, a cable holder and a knife for cutting the circular sheath. The line is the embodiment of everything that carries electricity. For example, cables to overcome the spatial distance, high voltage line, telephone line, manual line, installation line, etc.
Then divide the length of the wound wire by the number of strands. The resulting value will be wire section diameter.
However, the following must be taken into account:
- the more cores you wind on a pencil, the more accurate the result will be, the number of turns should be at least 15;
- press the turns tightly against each other so that there is no free space between them, this will significantly reduce the error;
- take measurements several times (change the measurement side, the direction of the ruler, etc.). A few results obtained will help you again avoid a large error.
Pay attention to the cons this method measurements:
The cable is sheathed electrical wire. The cable can also be made up of several strands, insulated wires or wires. However, the word cable is always connected to an earth cable, i.e. to a cable that is buried in the ground.
What is the difference between line diameter and line cross section?
The cable diameter indicates the outer diameter of the cable. Thus, the cable size is determined by the maximum diameter measured on the outer insulation. The conductor cross section is the cross section of the wire and is the end surface of the cutting wire material. Only conductive components are used as a basis, insulating material is not included. For strands, the ends of individual thin wires are added. By the way, some "air" remains, for example, a thin-wire cable thicker than a solid line with the same cross section.
1. You can only measure the cross section of thin wires, since you can hardly wind a thick wire around a pencil.
2. To begin with, you will need to purchase a small piece of the product before making the main purchase.
The formula discussed above applies to all measurements.
Method three. We use a table. In order not to carry out calculations according to the formula, you can use a special table in which specified wire diameter? (in millimeters) and the cross section of the conductor (in square millimeters). Ready-made tables will give you more accurate results and save you a lot of time, which you don't have to spend on calculations.
In Europe, the cross section is usually expressed in mm 2. In particular, in the field of mechanical engineering, robotics and transport, sensors are used to a large extent, the signals of which must be transported to the control unit. The operating conditions for these cables are extremely difficult as they are exposed to dirt, moisture, corrosive substances, heat or cold and strong movement during operation. Accordingly, a wide variety of demands on the cable sheath are high.
What is the correct stripping length?
The correct strip length is an important component for proper contacting and is determined by the type of joint being planned. Manufacturers of, for example, terminal clamps, cable sheaths or wire end ferrules indicate them on the respective packaging.
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Conductor diameter, mm |
Conductor cross section, mm 2 |
Instruction
However, special antenna cables are required to connect to the router. But most recently, however, the question arises, which cables are the best? As we shall see, the answer is not as trivial as one might think. Therefore, in the following guide, we help with the selection of the right cable, show what to consider and where to order it is ultimately cheap.
As with selection, the formula “bigger and more expensive = better” doesn’t necessarily apply. In a purchase decision antenna cable Several factors play an important role - the price is one. Ultimately, this means that a group of connecting cables is ideally suited to the personal needs of each person, depending on the purpose of use, amounts of money and local conditions. The importance of the legal framework also plays a role. All of this is shown in the following sections.
Measurement diameter a wires use a caliper to carry out in the absence of voltage. Any caliper, whether mechanical or electronic, has metal jaws capable of conducting current. If the wire is covered with a layer of insulation, measure its cross section without taking into account its diameter a.
When buying, the customer, in addition to the price, should include three important factors in the decision-making process. On the one hand, the required length, damping properties and mechanical properties of the cable itself. There is also a compromise between them. So, for example: the shorter the cable, the lower the attenuation, but the more difficult it is to choose the location of the antenna. The higher the price, the lower the damping loss. But also a higher cross section, so that the bending radius increases. Let's first see what this means in detail.
However, this usually increases the distance to the router that must be connected to the bridge. Exceptions are cables with a length of 5 - 10 meters. In principle, when choosing an installation site, make sure that the required length remains as short as possible and less than 15 meters. However, with each meter, the so-called damping increases. Low loss cables may be used.
To translate the section specified in the reference book wires in his diameter, use the following formula: D=2√(S/π), where S is the area of the conductor (mm²), D is diameter conductor (mm), π - the number "pi", 3.1415926535 (dimensionless value).
For reverse translation ( diameter and into a section) use the same formula, converted as follows: S \u003d π (D / 2) ², where D - diameter conductor (mm), S - conductor area (mm²), π - pi number, 3.1415926535 (dimensionless value).
The signal attenuation is physical property metal conductors and therefore also coaxial cables. Simply put, the obtained and expensive purchased antenna gain, For example, 10 dB, with a continuous length of cable. How high this, in turn, depends on several factors. When specifying damping values, it is therefore necessary to ask what useful range they are specified.
You can also find specific values in the comparison table. The quality and structure of the cable also affect attenuation. The smaller the cross-section of the inner conductor in a coaxial cable, the worse the material and shielding, the more unfavorable the attenuation characteristics, and one antenna gain is lost per meter. More expensive cables, on the other hand, offer double shielding and high quality materials - both in the conductor and in the dielectric and shield braid.
Cross section of stranded wires take equal to the sum of the sections of the individual conductors included in it. Sum them up diameter s is pointless. Calculations can also be multi-stage. So, for example, to find the equivalent diameter stranded wires, calculate the cross section of one of its cores, multiply by their number, and then translate the result again into diameter.
Take wire from diameter ohm or cross section exceeding the value calculated or indicated in the table, it is possible, but too thick wires it can be inconvenient to use: they can, for example, pull the terminal out of the terminal block with their own weight. Apply the same wires With diameter ohm or cross section less than the calculated or indicated in the table is impossible.
Cylindrical hollow conductors (such as those found in coaxial cables) have two diameter a: external and internal. According to them, calculate, respectively, two sections: external and internal. Subtract one from the other, and then convert the result to the equivalent diameter.
Strip the cable cores. Using a caliper, or rather a micrometer (this will allow for a more accurate measurement), find the diameter of the core. Get the value in millimeters. Then calculate the cross-sectional area. To do this, multiply the coefficient 0.25 by the number π≈3.14 and the value of the diameter d squared S=0.25∙π∙d². Multiply this value by the number of cable cores. Knowing the length of the wire, its cross section and the material from which it is made, calculate its resistance.
For example, if you need to find the section copper cable of 4 strands, and the measurement of the diameter of the strand gave a value of 2 mm, find its cross-sectional area. To do this, calculate the cross-sectional area of one core. It will be equal to S=0.25∙3.14∙2²=3.14 mm². Then determine the cross section of the entire cable for this, multiply the cross section of one core by their number in our example, this is 3.14 ∙ 4 \u003d 12.56 mm².
Now you can find out the maximum current that can flow through it, or its resistance, if the length is known. Calculate the maximum current for a copper cable from the ratio of 8 A per 1 mm². Then the limit value of the current that can pass through the cable taken in the example is 8∙12.56=100.5 A. Keep in mind that for an aluminum cable this ratio is 5 A per 1 mm².
For example, the length of a cable is 200 m. To find its resistance, multiply the resistivity of copper, ρ in Ohm∙mm²/m, by the length of the cable, l, and divide by its cross-sectional area S (R=ρ∙l/S). Having made a substitution, you will get R=0.0175∙200/12.56≈0.279 Ohm, which will lead to very small losses of electricity during its transmission through such a cable.
Sources:
- how to find out the cable size
Often find the right the wire to connect one or another device is problematic, given their total number in the hardware configuration of a modern computer.
Instruction
If you need to find the wire connecting the monitor to the video card, pay attention to a thick cable with a diameter of about 1 centimeter with two similar wide plugs on both ends of the blue or white color. The white plugs are used to connect the monitor to the digital output from the video card, and the blue plugs are for the analog output.
To determine which one you need, pay attention to the presence of connectors in the devices. If your monitor or video card supports one, but different connection interface, which happens extremely rarely, use a special DVI-VGA adapter that usually comes with a computer or monitor.
