You will need
  • tube;
  • roulette;
  • - caliper;
  • - the range.
Measure a tape measure or measuring tape the circumference of the pipe, to do this, wrap it around and look at the value on the scale. Next, divide the resulting value by the number of PI = 3,1415. As a result, you will receive the outer diameter of the pipe.
If you have a caliper, you can measure the outer diameter directly (for pipes up to 15 cm). To do this, grasp the tube by the jaws of the tool and view on a double scale, how many cm is the diameter.
In order to know the internal diameter, measure the wall thickness on the cut pipe. Measure with a ruler or caliper (the second method, of course, more precisely). Subtract from the outside diameterand wall thickness, multiplied by two the resulting number is the internal diameter.
Often notations are made of tubes in inches. If you have measured in inches, try to translate them into inches. To do this, multiply the diameter at 0,398 and you will get the size in inches. On the contrary, you can bring the diameter in inches to centimeters, just multiply it by 2.54.
When choosing a towel warmer or other works for which you need to know the diameter of a standard plumbing pipeheld in your home, use the following simple way. Attach a line to the pipe and estimate its approximate diameter. If the eye is seen, that the tube has a width of about 32 cm – safely make the conclusion that the landing diameter of its 1 inch. Size 25-28 cm corresponds to a standard pipe of ¾ inch and the value in the 16 mm – 1.2 inches.