Liquid level check (bottles, shampoo, detergent)
A group of bottles leaving the filler is captured in one frame as it passes a wide backlight. In each bottle the liquid surface is found as an edge and compared with the min–max window; an under- or over-filled bottle is blown off the line.
The level and deviation from nominal of every bottle are sent to the line PLC; a bottle outside the window is blown into the reject bin. The group chart is shown on the operator display and the level trend feeds back to the filler.
- 01 Infeed
- 02 Trigger
- 03 Acquire
- 04 Measure
- 05 Decide
The fill group approaches the station three bottles at a time.
- Most deviating level
- —
- Deviation
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
In a clear bottle the surface of the coloured liquid competes with the ribbed body and the label edge; right after filling, foam and sloshing move the surface by a few millimetres. Bottles sway on the belt and the measurement has to be made in groups while the line keeps running.
Solution approach
A wide backlight turns the bottle group into silhouettes; the liquid column stays dark and the empty volume bright. For each bottle the liquid–air edge is found in a vertical search window and referenced to the bottle shoulder, so swaying on the belt does not affect the result. A short strobe removes motion blur.
Process steps
- 01
Infeed
The fill group approaches the station three bottles at a time.
- 02
Trigger
The photo-sensor sees the first bottle of the group; capture is timed from belt position.
- 03
Acquire
The backlight strobes and the silhouettes of all three bottles are captured in one frame.
- 04
Measure
In each bottle the liquid surface is located and measured in millimetres.
- 05
Decide
The measurements are compared with the min–max window; the deviating bottle is flagged.
Related applications
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