Measurement of diameterand wire caliper to exercise in the absence of stress. Any caliper, regardless of whether it is mechanical or electronic, metallic sponge capable of conducting current. If the wire is covered with insulation layer, the dimension of its cross section to exercise without regard to its diameter.
Use to Express the diameterand cross-sectional area of conductors the unit of measurement adopted in electrical engineering respectively, millimeters and square millimeters (abbreviated as electricians call them "squares").
To put is specified in the reference section of the wire in its diameter, use the following formula:D=2√(S/π), where S - area of conductor (mm2) D - diameter of conductor (mm), π is the number "PI", 3,1415926535 (dimensionless value).
For a reverse translation (diameterand section), use the same formula transformed as follows:S=π(D/2)2, where D - diameter of conductor (mm), S - area of conductor (mm2), π is the number "PI", 3,1415926535 (dimensionless value).
The cross section of stranded wire , take is equal to the sum of the cross sections of its constituent individual conductors. To summarize their diameters pointless. Calculations can be multistage. So, for example, to determine the equivalent diameter of the stranded wire, calculate the cross-section of one of the cores, multiply by their number, and the result is then again put in the diameter.
Take the wire with the diameter ofω or cross-section than the design or specified in the table value, it is possible, but too thick of wire to use is embarrassing: they can, for example, pull out the terminal from the terminal block's own weight. Use the wire with diameterom or a cross section less than the calculated or specified in the table.
Hollow conductors of cylindrical form (for example included in the coaxial cables) have two diametera: external and internal. Them calculate, respectively, two sections: external and internal. Subtract one from the other, and then the result is translated into an equivalent diameter.