According to the different process requirements, steel pipe length measurement system has following methods.

1, The grating length measurement

The basic principle is: the outer ends are provided two fixed length steel grating, utilizing rodless cylinder near both ends of the steel grating drive, using light interference realize the measurement of the length of the pipe. It is characterized by high accuracy. But the scale is expensive and difficult to maintain, the impact of dust and vibration are sensitive site.

2, The camera length measurement.

Camera length measurement is the use of image processing to achieve pipe length measurement, the principle is equidistant installed in a section of pipe on the roller conveyor series of photoelectric switches, plus light source and the camera in the other section. When the pipe through the region, can be determined by the camera intake pipe length image on the screen at the position according to a photoelectric switch. Features are available for online measurement, pipe length of the data can be obtained by measuring the length of the area at the time, no interval. Shortage is: If you do not ad hoc light source, the light pipe will be subject to outside interference, while adopting ad hoc sources Because the tube after the tube end chamfering high brightness and reflection of light is very strong, likely to cause reading errors.

3, The encoder measuring length

The principle is mounted on the cylinder of the encoder, to promote the use of steel cylinder rollers movement, equidistant series of photoelectric switches installed on the other side, when the pipe was hit photoelectric switch cylinders push the tube end, from recording encoder readings converted the stroke of cylinder, so you can calculate the length of the tubes. Characterized by the need to raise steel measuring length. In addition, there are some photoelectric switch detects the error, you may need to be fully measured.

4. Improved length measurement encoder

This method is an indirect measurement by measuring the distance between the two end faces of the respective pipe between the reference point, the length of the pipe measured indirectly. At both ends of each pipe length measurement set a station car, the initial position is zero position, spacing L. Then move to the respective pipe length Editor tube ends running distance (L2, L3), L-L2-L3, is the length of the pipe. This measurement volume to overcome the huge steel production site environment is complex, measuring mechanism can not pass through the lower part of the supporting steel gantry and other difficulties. This method is easy to operate, the measurement accuracy within ± 10mm, repeatability