Method and characteristics of measuring length of straight seam steel pipe

1. Length measurement with grating ruler

The basic principle is that two fixed length grating scales are respectively provided on the outer sides of the two ends of the straight seam steel pipe, and the rod scale cylinder is used to drive the grating scale close to the two ends of the steel pipe. The interference of light is used to measure the length of the straight seam steel pipe.

Features: High accuracy. However, the grating ruler is expensive and difficult to maintain, and is very sensitive to the effects of dust and site vibration.

2. The camera measures the length.

The camera length measurement uses image processing to measure the length of the steel pipe. The principle is to install a series of equidistant photoelectric switches on a certain section of the straight seam steel pipe conveyor roller, and add a light source and a camera on the other section. When the steel pipe passes through this area, the length of the steel pipe can be determined according to the position of the photoelectric switch at a certain place on the screen through the camera to capture the image.

Features: On-line measurement can be achieved, the length data can be obtained when the steel pipe passes through the length measurement area, without interval. The disadvantage is that if the special light source is not used, the steel pipe will be disturbed by external light. After the special light source is used, the steel pipe has a high brightness after the chamfer, and the light reflection is strong, which is easy to cause reading errors.