The purpose and use of tape measure
Measure the size or distance of longer objects.
The tape measure is mainly composed of eight parts: a shell, a ruler, a brake, a ruler hook, a strap, a ruler spring, a fall protection cover and a label. The specific functions are as follows:
1. Shell: ABS new plastic, with shiny texture; anti-drop, wear-resistant and not easy to deform.
2. Ruler: 50# first-grade strip steel with a thickness of 10 wires (0.10mm) is used; the ruler surface is the most advanced environmentally friendly paint: odorless, smooth and wear-resistant, colorless
Bright colors, clear and bright scales
3. Braking: With upper, side and bottom three-dimensional braking, the hand control feels stronger.
4. Ruler hook: The rivet ruler hook structure is not easy to deform and ensures more accurate measurement.
5. Carrying straps: rubber and nylon; high-grade and high-quality; strong and durable, good hand feeling.
6. Foot spring: generally 50# carbon steel, 65# manganese material: strong toughness and high accuracy.
7. Anti-fall protective cover: high-quality plastic to prevent breakage and collision damage, and enhance durability.
8. Labeling: It can be produced according to customer requirements.
A measuring device includes a measuring mechanism such as a tape with a tape, the measuring mechanism has an end hook with a hook, and
A mechanism such as a magnet for selectively fixing the tape to an object, such as a tube, and the selective fixing mechanism is connected to the measurement
The end hook of the mechanism. A measuring device, comprising: a measuring tool, the measuring tool has an end hook; and a magnetic tool, the magnetic tool
The tool is embedded in the end hook.
(1) Direct reading method
When measuring, the zero scale of the steel tape is aligned with the starting point of the measurement, and an appropriate pulling force is applied (the pulling force is subject to the identification pulling force of the steel tape or the calibrated pulling force on the ruler.
Use spring scale to measure), directly read the scale on the ruler corresponding to the end point of the measurement.
In some parts where the steel tape measure cannot be used directly, a steel ruler or a square ruler can be used to make the zero scale align with the measuring point, and the ruler body is consistent with the measuring direction
; Use a steel tape to measure the distance to a certain full scale on a steel ruler or square, and measure the excess length with the reading method.
(3) Several errors in steel tape measurement
The more accurate steel tape must be verified when it leaves the factory and after a period of use, and the temperature, tension and ruler length at the time of verification must be indicated. Mark on the ruler
The length of is the nominal length, and the difference between it and the actual length is called the ruler length correction Δl. When the ruler is subjected to different tensions, the ruler length will change. To avoid
To avoid this change, it is required to use the steel tape in accordance with the tensile force marked on the ruler. The length of the steel tape will change at different temperatures, so it must
Use a function with temperature t as a variable to express the ruler length