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Tin Channel Principle
FLOATSCAN Advanced
Customer Training
Revision 1.4, 23/Feb/2010 CN
Page 1 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Option - Tin channel
Integrated additional channel to FLOATSCAN Advanced
Two different resolutions available for 100µm or 300µm tin detection
The detection of top tin and bottom tin defects is done by its shiny surface
(like a mirror) on glass from underneath (top tin) and above the glass (bottom
tin)
• uses mirror like interface between metallic tin and glass surface
One tin detection head is located above the glass ribbon inside of the camera
bridge
• No discrimination between top tin and bottom tin defects possible
• The distances for the scan lines between top tin and bottom tin channel are
50mm in glass flow direction - Please note therefore the position accuracy of tin
defects in glass flow direction is +/- 25mm
– Please consider for cutting and optimization system
Tin-Stain (Tin with distortion - hot end tin or drip)
• Detected by the Moiré Channel
Page 2 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Appearance of tin defects
looking at tin defects
in transmission
(Moiré Channel)
looking from above
No discrimination from any
other absorbing defect
possible
Page 3 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Tin channel measurement principle
Page 4 / V1.4, CN © ISRA
looking at reflection of shiny
surface on glass side
Due to the reflection an easy
discrimination from any other
defect is possible
FLOATSCAN Advanced – Option Tin Channel
Bottom tin channel – detail measurement principle
Tin
Head
Intensity
Transport direction
Glass ribbon
Pixel
Reflecting bottom tin defect
Page 5 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Top tin channel – detail measurement principle
Tin
Head
Reflecting top tin defect
Intensity
Transport direction
Glass ribbon
Pixel
Page 6 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Tin-Channel - Measurement principle - detail
Bottom Tin Channel
Top Tin Channel
Moire Channel
50mm
Reflection bottom
Reflection top
Page 7 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Tin-Channel - tin head principle
Remember: one camera is used -> therefore no discrimination between
top and bottom tin defects possible
Front view
1st surface mirror for
bottom tin channel
Tin camera
Side view
Bottom Tin Channel 30%
Top Tin Channel 70%
Beam splitter
Page 8 / V1.4, CN © ISRA
Protection cover for
mirror and beam
splitter
FLOATSCAN Advanced – Option Tin Channel
Difference tin without / with distortion
Bottom Tin
without distortion
e.g. Tin Drip
(Tin with distortion)
Detected by moiré channel
Top Tin
Without distortion
Remark: Reflective surface is nearly infinite
small
Page 9 / V1.4, CN © ISRA
FLOATSCAN Advanced – Option Tin Channel
Size of tin defects – mirror like surface
Remember
• The tin channel of the FLOATSCAN - Advanced uses the mirror like
interface between metallic tin and glass surface for detection and
sizing.
Overall
tin size
reflecting size of tin defect = detected tin size
Page 10 / V1.4, CN © ISRA