Direct answer
Select a checkweigher from the smallest and largest pack, line speed, required detection capability, environmental conditions, product stability, reject method and the role it plays in quantity control. A dynamic check result is only useful when the pack is stable and the system is verified with known test loads.
Why this matters
An unsuitable conveyor, short weigh bed, vibration or unstable product spacing can create apparent weight variation that is not present in the filled pack.
Decision table
| Requirement | Question | Why it matters |
|---|---|---|
| Pack range | Weight, length, base and centre of gravity | Weigh time and stability |
| Line rate | Actual spacing and peak flow | Available measurement time |
| Accuracy | Smallest defect that must be distinguished | System capability |
| Reject | Pack type and failure response | Containment |
| Data | Batch records, trends and feedback | Control and traceability |
Information to collect
- Measure the complete pack and weight range.
- Define line rate and actual product pitch.
- State the required decision threshold and purpose.
- Record vibration, airflow, washdown and temperature conditions.
- Choose a reject and reject-confirmation method.
- Agree test-piece and challenge frequency.
Practical method
- 1
Stabilise product spacing before the weigh conveyor.
- 2
Select a weigh section long enough for the pack and speed.
- 3
Protect the system from vibration and drafts.
- 4
Validate rejection and fail-safe responses.
- 5
Use trends for filler adjustment only after measurement stability is proven.
Common mistakes to avoid
- Selecting on maximum weight only.
- Confusing display resolution with usable accuracy.
- Allowing touching packs onto the weigh belt.
- Using an unconfirmed reject.
- Feeding back to the filler from noisy measurements.
Questions people also ask
Can a checkweigher replace filler control?
No. It verifies finished packs and may provide feedback, but the filler still needs a capable dosing process.
What affects dynamic weighing accuracy?
Pack stability, belt speed, weigh time, vibration, drafts, product movement and calibration all affect the result.
Is a trade-approved system always required?
The legal and commercial role must be defined with competent advice; not every process uses the checkweigher in the same way.
What should a factory test include?
Run the smallest and largest packs at target speed, challenge each reject condition and verify repeatability with known loads.
Official and primary sources
These references support the regulated, standards-led or security points in this guide. Check the current source before making a project decision.
Continue from the requirement to the equipment
Use the specialist route that matches the product, pack and process. Final suitability requires representative samples, output targets and site information.