Segmented, feet belt tensioning force of changes, according to the type (1), the per meter applying tension with every 5 m, 10 m exert tension, foot force different belt length, and affect the measurement result. Steel tape test temperature and foot temperature linear expansion coefficient of verification, gauge and gauging in the regulation of the isothermal temperature, equilibrium temperature time not less than 4 hours. Temperature measuring instrument error of temperature gradient along the axis of the measuring air temperature, the temperature of the gauge and keychain tape measure gauging of different linear expansion coefficient, directly affect the measurement result. In the process of steel tape test, many factors directly affect the measurement result, such as the line width of gauge and gauging, temperature fluctuations, feet with gravity, etc. These factors or overlay or offset, sometimes naked eye differentiates readings are difficult to detect, by reading microscope readings when necessary, the verification regulation rules must be strictly implemented, to get more reliable measurement results.
Because of the limitation of length of mini tape measure verification platform span beyond verification platform length of steel tape will * fractionation method should be used in measurement. Increase as the number of segments, the cumulative error * big, piecewise measuring reading should accumulate before every deviation values or error value. Steel tape can be divided into, since the volume type tape, brake type tape, shaking volume type tape measure. Other names are: steel tape steel tape, steel box of feet. Followed by fiber tape, is the tape measure, you often see a lot of people say tape, waist feet, tailor feet (tape) belong to this. In the south of our country and Hong Kong area is often called a flexible rule or feet. Standard of steel tape structure principle and structure of common steel tape is the same, but there are differences in appearance, followed by the different purposes. Standard steel tape is mainly used for verification personalized tape measure of ordinary steel tape, of course, also can be directly used in large equipment installation and fine * engineering survey. The uncertainty of plus or minus (10 + 10 l) microns. Steel tape by the respective laboratory of error of standard devices, environmental conditions and other factors. Below to adopt comparative measurement, measurement standard is a standard steel tape, for example, that steel tape error value when problems should be paid attention to. Steel tape test