Technology selection guide
Vision, X-Ray or Checkweigher Fill Inspection?
A practical way to choose the inspection principle for transparent and opaque packs, liquids, powders, bottles, jars, cans and solid products.
Short answer
Choose the method that can see or sense the real defect.
Use machine vision when the fill boundary or product feature is consistently visible. Use X-ray when opaque material, metal, coloured glass or dense decoration hides the contents. Use weighing when mass is the critical measure. Use presence or counting logic when completeness—not level—is the real requirement.
No technology should be selected from the pack name alone. Representative samples, line speed, product behaviour, tolerances, hygienic needs, available footprint and the reject strategy complete the decision.
Method comparison
Match the sensing principle to the pack.
| Method | Best fit | Typical checks | Important considerations |
|---|---|---|---|
| Machine vision | Clear, translucent or open packs with a visible feature | Fill height, foam band, cap, label, colour, shape, code and presence | Lighting, contrast, reflections, product movement, labels and ambient conditions |
| X-ray | Cans, cartons, coloured glass and opaque plastics | Fill region, gross underfill or overfill, missing product and selected integrity checks | Product density, pack geometry, wall thickness, required contrast, guarding and integration |
| Checkweighing | Applications where pack mass is the required measure | Underweight and overweight packs | Tare variation, vibration, line speed, product movement and legal-metrology requirements |
| Presence/count sensing | Open containers, trays, cavities, kits and separated products | Presence, exact count, empty cavity and pack completeness | Overlap, orientation, presentation, resolution and the last clear view before closure |
Five-step selection
Turn the inspection question into an engineering brief.
A useful brief describes the defect, the pack and the production response. It gives sample testing a clear pass/fail target.
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01
Define the defect
State the unacceptable low, high, missing, count, closure or appearance condition.
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02
Describe variation
Include genuine good variation in packs, products, suppliers, batches and environment.
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03
Map the line
Record speed, spacing, conveyor movement, footprint, interfaces and reject distance.
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04
Prove samples
Test representative good and bad packs before fixing tolerances and technology.
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05
Control failure
Agree rejection, confirmation, alarms, line stops, records and operator action.
Common selection routes
Continue with the application that matches your pack.
Each page explains the practical variables, checks and questions for a focused inspection task.
Practical answers
Questions production teams ask.
Final performance is application-specific and is confirmed using representative packs, products and line conditions.
Ask an engineerWhat is the best way to inspect a transparent bottle?
Machine vision is often the first method to assess because controlled transmitted light can reveal the visible product boundary. Container colour, labels, embossing, foam and product contrast still need to be tested.
How do you inspect fill level in a metal can?
A visible-light camera cannot see through metal. X-ray or another penetrating sensor can be assessed to measure the fill region through the closed can.
Is fill height the same as fill weight?
No. Fill height is a geometric or level indication. Weight is a mass measurement. Product density, container geometry, foam and settling can change the relationship between the two.
Can one inspection station check caps and labels too?
Often yes when the required views, lighting and image resolution are compatible. A multi-camera cell may combine fill level with cap, label, colour, code, shape and presence checks.
What information is needed for a line assessment?
Provide pack drawings or photographs, representative good and bad samples, product details, line speed, pack spacing, conveyor information, fill tolerances, available footprint and the required reject and reporting response.
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