Theory
Metallic tape
The tape consist of varnisheet strip of line or cloth 12 to 15 mm wide. Having very fine brass or copper or bronze wires woven into it to prevent it from elongations and twisting is knows as metallic plate. These are available in various length e.g. 10m, 20m, 30m. each meters length is divided into diameter to centimeter. It is available in leathering cover treated with winding device. The zero end in provided with brass ring length. Through metallic tapes are used in all engineering survey such as for taking measurement of offsets and other subsidiary but their used is restricted for very accurate measurement.
Diagram
Steel tape
The tape which consist of a light steel strip of width 6 mm to 16 mm. it is more accurately graduated each meter length is divided into 20 m equal parts. The each part is equal to 5 mm first 10 cm of length is graduated upto 2 mm. it is also provided with a brass ring at the zero end. The tape is provided with a length of 2 m, 10 m, 20 m, 50 m The tape is provided with rust proof metal case having a suitable winding devise for accurate measure this type of devise is used. It is also used for testing chain it is lighter delicate it will not with stand field it should be wound after cleaning and oiling, so that it may not rust.
