Sirius - Edge pinhole & crack detector and width measuring system



Sheet metals are manufactured using continuous process to stretch the raw material and form a steel sheet of some tenth millimetres of thickness.
The stretching process of the sheet metal on continuous line can induce a lack of regularity in the width of the strip.
This width is regulated with the edge trimming machine or with the slitting machine, but these tools should be controlled afterwards.
This could lead also to some non regularity along the edge of the foil, what is called “crack”.
In order to detect those defects and to guaranty a perfect quality of the strip which is finally coiled, we propose an equipment called Sirius to measure permanently the width and to permanently check the lack of crack.

View of the mechanical structure showing the two detectors

The benefits for the customer are :

  • To deliver exactly the width to the end user as ordered and not more: money saving.
  • To avoid the presence of cracks : quality.

In addition Sirius gives both edge positions for a steering system or belt alignment system.

Sirius detector allows to measure and survey at a run speed of 15m/sec a metal sheet of thickness 0,15 mm up to 5 mm with variable width from 600 mm to 2000 mm with an accuracy of 0,2mm if periodic calibration is done.
Cracks of 0,2mm-width with a 1mm-depth are detected.

        View of Sirius with its protective covers


Width measurement : the strip passes through two optical detectors, like a laser barrier.
These detectors are mounted on a mobile axis and look for the edge’s strip.
When the edge is found, the mobile axis stops the movement.
If the strip moves later on, then the mobile axis moves again the detectors positions and try to continuously centre the sensor over the edge.
The combined position of the mobile axis and of the strip edge inside the detector gives the edge position regarding the equipment.
Making the sum of two edge positions gives the strip width.

Crack detection : the detector measures the edge position in a dynamic way and detects also some fast and small irregularities in the edge.
These irregularities are analysed permanently to signalize some cracks when the irregularity is too important.

Calculation : the associated industrial computer is receiving information of the 2 detectors in real time ; it makes analyse of the position, it indicates result and moves the mobile axis if necessary ; it closes a relay when a crack or a hole is detected ; it measures continuously the strip position. 


Performances of the standard product are the following ones:

- Detection of crack of a 0,2mm by 1mm or more
- Width measurement accuracy: +/-0,2mm with periodic calibration
- Strip thickness from 0,15 mm to 5 mm
- Maximum run speed : 1000m/min
- Width of sheet between 600 and 1400 mm for SIRIUS 1400
- Width of sheet between 600 and 2000 mm for SIRIUS 2000
- Range of temperature of functioning from + 15°C to + 70°C 


Dimensions of the structure :
2500 x 800 x 250 mm
or 1900 x 800 x 250mm

Dimensions of the control panel :

400 x 500 mm

Electric data :
230VAC 50 Hz / maximal consumption 100W / 16A

Interfaces :
Digital Inputs :
1 input to open the forks and 1 input to close them
Remote interface :
serial line to order the system or to receive data

Indications on defects are given by 4 mechanical output relays located in the control panel :
* 2 relays for crack detection, 1 for each side
* 1 relay indicating the width over limit
* 1 relay indicating the good functioning of the system


SIRIUS 1400 : strip’s width from 600mm to 1400mm
SIRIUS 2000 : strip’s width from 600mm to 2000mm


CEPHEE : pin-hole detector
CRATER : crack and hole detector
ORION : painting defect detector

Download Product Data Sheet


Réalisation SYSTONIC 2008