Measure tools in life are very common and are something we often use. Whether it is the length measurement of our clothes or the measurement of the distance and volume between objects, we need to use tools to measure tools to reflect specific data. Tape measure is one of the common measurement tools. Next Xiaobian will tell you about what makes a tape measure? Tape measure and reading method.
What makes a tape measure?
1, Stanley tape measure
Stanley STANLEY Hardware Tools (Shanghai) Co., Ltd., which began in 1843, is the world's tool expert under Stanley Black & Decker Inc., the world's leading manufacturer of fastening tools, among the top ten tape measure brands, Stanley Tape Measure It is the best choice for consumers because of its super straight length, wear-resistant and high-quality outer shell.
2, Sato measuring tape
Shanghai Sai Tuo Hardware Tools Co., Ltd., a well-known brand of tool box, is engaged in the production and import/export of manual tools and power tool products, as well as multinational companies that sell overseas.
3, Baogong tape measure
Shanghai Baogong Tools Co., Ltd., a well-known hardware tool brand, started in Taiwan in 1991. It is a manufacturer of professional hand tools/power tools/welding tools and test instruments. Its multimeter is well known.
4. Forgist tape measure
FORGESTAR Fugesite Mingkun Metal Tools (Shanghai) Co., Ltd., a brand under the German POPULAR Group, specializes in research, development, production and sales of hand tools, pneumatic tools and power tools.
5, easy to get tape measure
, Ltd., the top ten brand of hand tools, was established in 1998. It is a professional hand tool brand owned by Textron and a world-leading manufacturer and service provider of maintenance tools for industrial and mining companies.
6, Kunjie tape measure
Carnegie Tools (Shanghai) Co., Ltd., KUNJEK Kunjie, originated from Germany and entered the Chinese mainland market in 2002. It is dedicated to the design, development, production and sales of professional hand tools.
Shida Tools: Shanghai Shida Tools (Shanghai) Co., Ltd., the top ten brand of electric irons, a subsidiary of the American APEX Tool Group, a mid- to high-end tool brand, the maker of sleeve/wrench standards, and a global manufacturer of large-scale industrial manual and pneumatic tools. .
Tape measure
(a) Hand press the button on the tape measure, pull the head of the tape by hand, and then pull out the measurement.
Reading method:
1, direct reading method
During the measurement, the zero scale of the steel tape measure is aligned with the measurement starting point, and the appropriate tension is applied to directly read the scale on the ruler corresponding to the end point of the measurement.
2. Indirect reading method
In some locations where steel tape cannot be used directly, use a steel ruler or square ruler to align the zero mark with the measurement point. The ruler is the same as the measurement direction. Use a tape measure to measure the distance to a full scale on the steel ruler or square ruler. Yu Chang uses readings to measure out.
(b) The inner structure of the tape measure is only one axle and the outer steel ruler is wound. The ruler is wrapped around the axle. The wheel can also rotate but his center is pulled by the spring. When you pull the ruler, the wheel will be rotated with the spring and it will be hung again and again. When you release the spring Will pull the wheel back. Then the ruler also followed back.
Tape reading method
(1) Direct reading method
During the measurement, the zero mark of the steel tape measure is aligned with the starting point of measurement, and the appropriate pulling force is applied (the tensile force is determined by the steel tape measure or the calibrated tensile force on the ruler, measured by a spring scale), and the scale on the ruler corresponding to the end point of the measurement is directly read. .
(2) Indirect reading method
In some places where it is not possible to use the steel tape directly, you can use a ruler or square to align the measuring point with the zero mark. The ruler is in line with the direction of the measurement. Use a steel tape measure to measure a full scale on the ruler or square. The distance is measured by the reading method.
(3) Several errors in the measurement of steel tape
The more accurate steel tape measure must be verified and marked with the temperature, tension and length after it is shipped and after a certain period of use. The length marked on the ruler is the nominal length. The difference between the actual length and the actual length is called the ruler length correction Δl. When the ruler receives different tension, the ruler length will change. In order to avoid this change, it is required to use the marking force on the ruler when using a steel tape measure. The ruler length of the steel tape measure will also vary at different temperatures. Therefore, the length of the ruler must be expressed as a function of the temperature t. This is the ruler length equation. Its general form is: lt=l+Δl+α·l(t- T0)
The actual length of the lt steel tape measure at temperature t;
l nominal length of steel tape measure;
Δl length correction, that is, the difference between the actual length and the nominal length of the steel tape at the temperature t0;
α steel tape thermal expansion coefficient;
T0 steel tape temperature detection;
t The temperature at which the steel tape is used.
In the use of steel tape, the main causes of errors are the following:
A, the error of temperature change
The coefficient of thermal expansion of a general steel tape measure is α = 1.25x10-5, and the temperature difference per metre per degree changes is only 80,000 times. However, the same steel tape measure will have a large length change in a large temperature difference environment. Measurement results. The error in temperature variation has been taken into account in the ruler length equation.
B, pull error
The size of the pull force will affect the length of the steel rule. If you do not measure the pull force with a spring during the measurement, an error will occur. The modulus of elasticity of steel E=2X106KG/CM2, according to Hooke's law, a length error of ±1.8 mm is produced when the 30-meter foot length is within ±5 kg of tension error.
C, steel ruler is not horizontal error
When measuring the horizontal distance, the steel tape measure should be kept as horizontal as possible, otherwise there will be an error in the distance. For a foot length of 30 meters, an error of about 2.6 millimeters is generated when the height difference between the two ends of the ruler reaches 0.4 meters, and the relative error is 1/11,200.
What makes a tape measure? The measuring tape method and reading method are introduced here for everyone. The measuring tape is mainly used to measure length. It is also very convenient to use as an essential tool for daily life. Everyone must choose the quality of the tape measure and read the most accurate tape measure.
