Knowledge centre · Buying process
Filling machine acceptance testing: how to verify accuracy before you pay
A signed acceptance test is your only guarantee that the machine delivers what the datasheet promised. Make it precise.
1. Define acceptance before you sign the order
Do not wait until the machine is built to discuss testing. The acceptance protocol — product, fill volume, line speed, accuracy target and how samples are measured — belongs in the purchase contract. Without it, "acceptable" means whatever the supplier says it means on the day.
2. How to run a meaningful accuracy test
| Step | Practical guidance |
|---|---|
| Use your product | Water or substitute liquids test the machine, not your product. Accuracy claims (e.g. ±0.5%, error ≤1 g) must be demonstrated on the actual product. |
| Take enough samples | A handful of containers proves nothing. A practical minimum is 30–50 consecutive fills at production speed, weighed individually. |
| Weigh properly | Weigh the fill net (filled minus tare) on a calibrated scale; record every value, not just an average. |
| Check start and steady state | Include the first fills after a stop and fills at continuous speed — both matter in production. |
| Agree the metric | Decide whether acceptance is mean error, max deviation, or a percentage of samples within tolerance — and write it down. |
3. What else to verify at FAT
- Changeover: time and steps to change fill volume on the HMI.
- Cleaning: CIP cycle reaches the dosing path; disassembly where required is quick.
- Spare parts fit: seals and change parts fit correctly and are identified in the manual.
- Documentation: drawings, wiring diagrams, manuals and the acceptance report are complete.
4. At your site, repeat the core test
Factory acceptance is a strong signal, but installation at your plant introduces new variables — feed pressure, piping length, temperature, air supply. Repeat the core accuracy test at site acceptance with your product, at production speed, and keep the records. If results drift, investigate the installation variables first, not the machine.