Relating periodic marks on cold-rolled strip to the roll
Cold-rolled strip travels beneath upper and lower line cameras; oblique light reveals repeated marks. Defect spacing linked to encoder position is compared with known roll circumferences and a suspected match feeds a maintenance alarm.
Defect spacing and the suspected roll code enter the maintenance record; the operator display and stack light signal a roll-inspection alarm.
- 01 Rolling
- 02 Position
- 03 Marks
- 04 Repeat
- 05 Maintenance
The strip exits the rolls.
- Defect repeat spacing
- —
- Suspected roll circumference
- —
- Repeating marks
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
Changes in strip speed can distort defect distances inferred from frame intervals. Position information is needed to separate random marks from a repeating roll imprint.
Solution approach
Line images of both faces are acquired under oblique light; defect centres are registered to encoder positions. A repeat sequence is derived from successive centre spacings and compared with known roll circumferences. A match indicates a suspect roll for maintenance.
Process steps
- 01
Rolling
The strip exits the rolls.
- 02
Position
The encoder registers strip distance to the image.
- 03
Marks
Defect centres are located on both faces.
- 04
Repeat
Centre spacings are compared with roll circumferences.
- 05
Maintenance
The suspect roll feeds the maintenance alarm.
Related applications
Let us assess your application together
We test your sample in our laboratory and report on resolution, optics and lighting selection.