Handbag is a special high-precision technical work. According to its raw materials and structural characteristics, take the length should pay attention to the following matters:
First, the amount required by the flat on the table, the amount of its natural state of the length of the absolute material is not allowed to stretch, because many of the handbag is a scalable material. Otherwise the amount of length is longer than the physical length.
Second, the measurement of the distance between the two parallel lines, to make the ruler and the two parallel lines perpendicular to the starting point of the ruler can be fixed on a parallel line, the other end of the parallel line in another parallel to the teeth, the shortest scale is The distance between two parallel lines, because the vertical line of the shortest.
Third, the starting point of the foot and line coincidence, if the bone bag, do not see the line, the starting point from the bone center, the end to the opposite line or bone center prevail. (Paper length separately)
Fourth, the use of soft leather feet fold or bending material, the soft leather feet must be completely coincident with the volume, otherwise it will be long.
Five, read out the length of the object, the line of sight must be perpendicular to the scale on the ruler, if the line of sight left or right, will read longer than the length or short length, resulting in human error.
