Glossary · Packaging and intralogistics
Checkweigher
Also known as: Check weigher, Automatic catchweigher
German: Kontrollwaage
In packaging, a checkweigher is an automatic weighing instrument that weighs every package in a moving line and rejects packages whose weight is outside set limits.
- Intralogistics
- Standards
In one sentence
A checkweigher weighs every package on a moving line and rejects those outside set weight limits, for example underfilled packs.
Example
The checkweigher after the filler rejects cereal boxes lighter than 495 g into a locked bin and reports trends back to the filler control.
How it applies
- Engineering: A checkweigher has an infeed, a weighing conveyor on a load cell and a reject device. Feedback to the filler lets it correct the fill quantity automatically.
- Quality and legal metrology: Checkweighers often verify compliance with legal requirements for prepackages. Where they are used for legal purposes, they may be subject to legal metrology rules; OIML R 51 is the international recommendation for automatic catchweighing instruments.
- Operation: Regular functional tests with test packages check that rejects work. Test results are quality records.
- Documentation: Describe the test procedure, test intervals, limit settings and who may change them. Changes to limits should be traceable in an audit trail, especially in food and pharma.
Checkweigher vs. metal detector
A checkweigher checks the weight; a Metal detector checks for metal contamination. Lines often combine both with a shared reject system.