How to masterfully use a tape measure: quickly measure the diagonal of a TV, the diameter of a circle, pipes

Specialists in technical professions have a large set of tools: calipers, building level, square, laser rangefinder and many others. But at the same time, each of them carries a good old measuring tape in their bag. You can measure, if not everything, then a lot with a tape measure. For example, the diameter of a circle. Or pipes. Or the diagonal of the TV. It will help you quickly divide a rectangle into 3, 5 or more parts. We invite you to find out how to use it correctly.

How to measure diameter with a tape measure

There is nothing easier than measuring the diameter of a circle if you have a construction tape at hand. As we know:

The diameter of a circle is a straight line segment passing through the center and connecting any two points on it.

That is, in order to measure the diameter of a circle, you need:

1. Place the tape measure on the circle so that it passes through its center.
2. Measure the distance between two points on the circle. This will be the diameter.

The center is usually determined by eye. But you can also get confused (to get ultra-accurate results):

1. Using a tape measure and a simple pencil, draw several straight segments (from 3 to 5 pieces). They should, as it were, cut off the “sides” of the circle.
2. We measure the length of the first segment inside the circle. Divide the value in half. You don't need to use a calculator for this. It is enough to bend the tape measure in the middle (add the resulting value to zero).
3. We draw a new chord (straight segment) passing through a point on the circle and the middle of the first chord. We make sure that the segments are located at an angle of 90 degrees (see below for how to measure an angle with a tape measure).
4. We do the same with other chords.
5. The intersection of the perpendicular lines will be the center of the circle.

By the way, using a tape measure it is very easy to draw a circle of a given diameter. In many tapes, at the very beginning, at approximately a distance of 2.5 cm, there is a round hole. You can insert an awl or a nail into it and stretch the ribbon to half the required diameter (radius). Press the pencil to the body and draw a circle.

This same hole eliminates the need to involve a partner when you need to take measurements of 1 m or more. We hammer a nail into it. This way the tape is fixed on the surface and can be rolled out to its full length. And if the tape is not long enough, the body can serve as a continuation. Its size is usually 70 mm (indicated on the back cover).

How to measure an angle with a tape measure

A tape measure can be used to check the right angle of the walls. As you know, walls should be perpendicular to each other, and the angle between them should be 90 degrees at any height.

To check for distortion, do the following:

1. Measure two arbitrary distances from the center of the corner. For example, 1.5 on one wall and 2 m on the other.
2. Place pencil marks at the same height.
3. Make calculations: square the length of each segment and add the resulting values. Take the square root of the resulting sum. Example: (1.5×1.5)+(2×2)=6.25. √ 6.25=2.5.
4. We get the distance in m (cm) between two segments at an angle of 90 degrees. In the proposed version, the figure will be 2.5 m.

You can make it even simpler and use the table:

You can use a tape measure to measure not only the angle between walls, but also between the wall and the floor, furniture parts, etc. If you divide the values ​​by 100, we get the length of the diagonal in millimeters (for checking the angle in small parts).

To measure an angle of 45 degrees, divide the value in half. Example: 141.4 ÷ 2 = 70.7 cm diagonal between 100 cm segments. To get an angle of 30 degrees, divide the value by 3, etc.

How to measure a pipe with a tape measure

A construction tape can be used to measure the pipe. It’s easier to measure it from the end (see how to measure the diameter of a circle with a tape measure). By measuring the distance from wall to wall, you can find out the internal diameter. If you measure the pipe along with the walls, we get the outer diameter.

But more often it happens that there is no access to the end of the pipe. Then the formula is used to measure the diameter: D=L÷3.14.

You need to do the following:

1. Wrap the pipe with tape (measure the girth). It is important that the beginning of the tape is accurately connected to the division. We get the circumference.
2. Divide the circumference by Pi.
3. Example: the girth is 28 cm. 28÷3.14 = 8.91 cm pipe diameter.
4. For more accurate calculations, subtract twice the thickness of the tape measure and another 0.2 mm (correction for its fit to the surface) from the obtained value.

This way the outer diameter of the pipe is determined. The internal volume is indicated in the accompanying documentation or the pipe itself in inches. To convert it to centimeters, the indicators are multiplied by 2.54. And, conversely, to convert centimeters to inches, divide by 0.398.

How to measure the diagonal of a TV with a tape measure

Nothing complicated here either.

The TV diagonal is the distance from one corner of the screen to the other. It is measured in inches.

The inch has been taken as a basis since the appearance of the first televisions in the United States. Back then they were kinescope and displayed an image in the shape of a rectangle. The diameter of the kinescope completely coincided with the diagonal of the screen. Therefore, they began to measure it. This is much more convenient than using width and height measurements.

How to measure the diagonal of a TV:

1. We apply the tape measure to one of the corners of the screen (not the TV, but the screen).
2. We lead diagonally to the opposite corner.
3. Let's see how many centimeters we got.
4. Divide the number of centimeters by 2.54 (1 inch is 2.54 cm).
5. For example, 56 cm ÷ 2.54 = 22.047. We round up and get a diagonal of 22 inches.

You can find out the TV diagonal in another way. For example, look at the technical data sheet. Or look for relevant information on the back cover. Also, the diagonal sizes of TVs are available on the Internet. Just enter the brand and serial number into the search.

Questions and answers

Question: How else can you use a construction tape?

Answer: Using a tape measure, you can quickly divide the work surface into the required number of parts. To do this, you need to take a number on the tape measure that is larger than the width of the workpiece, and at the same time a multiple of the value by which you need to divide the distance. For example, the width of plywood is 87 cm. You need to divide the material into 3 parts. We take the value 90. We find it on the tape measure. We apply it to the plywood (it turns out that the tape lies at a slight angle). We make marks every 30 cm (90÷3).

Question: Which roulette is better?

Answer: The choice of roulettes today is huge: automatic, with voice-activated menus, many functions and the option of storing measurements.But still, the main thing in the tool is the accuracy class (preferably the first), the length of the tape (universal - 5 m) and wear resistance (nylon and steel).

You also need to know how to use a measuring tape. With the right approach to measurements, it can replace many other tools when building a house, making furniture, or plumbing work. A non-standard approach trains the mind and ingenuity. The main thing is that the tape measure has a high accuracy class. It is also important to always use the same measuring tool. On different roulettes, the divisions often do not coincide.