Instruction

1

To use any available measuring devices. the ideal option is to use a micrometer; it is possible to replace it with a caliper. In an extreme case, fit a tape measure or ruler with clearly visible divisions and a pencil (or a long thick nail). As is known, the area of a circle (a

**cross section****of the wire**is the circle) can be found by the formula S=?r2 or S=0.25?D2; r is the radius**of the wire**, D is its diameter. Directly the radius of the conductor is difficult to measure, and no reason is sufficient to determine the diameter. Since ?=3,14, one may assume that S=0,78D2, the accuracy obtained is quite reasonable.2

Simply put, to know the cross-sectional area, measure with a micrometer (or caliper – it's more affordable) diameter core

**wire**, the result is to multiply himself, that out – even multiply by 0.78. When determining wire size large diameter (2.5 mm) to simplify calculations it is possible to use a factor of 0.8. When measuring wires with a diameter of 0.5 mm or less, it is possible to apply a factor of 0.7.3

In the absence of such precision measuring instruments like Vernier caliper or micrometer, you can determine the diameter using a ruler. For this you need to reel in the object like a pencil, for ease of calculations - multiple of ten, the number of turns of the examined

**wire**; the coils will be greater, the better the end result. The winding should be dense, turn to turn. You should then measure with a ruler the length of the resulting winding length divided by the number of turns, the result will be the diameter of the core**wire**. Further, it is possible to calculate**the cross section of the****wire**as described above.4

To determine

**the cross section of**stranded**wire**in two ways. In the presence of micrometer or caliper is measured in**the cross section of**one core, the result is multiplied by the number of cores. To measure**the cross section**stranded**wire**with a ruler, it is necessary to twist the pliers in the "pigtail" and then act as described above.