Equipment, calibration and maintenance

Procedure

1. Assign a unique ID and file to each critical instrument. Define use, operating range, accuracy and acceptance criteria.
2. Confirm suitability for batch size and materials. Balance readability does not mean every small weight is reliable.
3. Schedule calibration and maintenance using risk and manufacturer instructions. Retain certificates and reference-standard traceability.
4. Perform defined pre-use checks: balance zero/stability, appropriate pH buffers and sensor checks. Record actual values.
5. For mixers record the tool, vessel geometry, load, time and speed. The same speed setting does not ensure equivalent mixing in another system.
6. Label failed equipment out of service and assess batches since the last acceptable check. Return it only after documented restoration.

Additional detail

Before using a balance document checks with suitable reference weights and confirm its qualified minimum weight. For pH use suitable certified buffers and record temperature and slope/offset according to the instrument manual. A failed check requires removing the instrument from use and assessing batches since its last acceptable check.

The qualified minimum weight depends on the balance, installation and task-relative tolerance. A calibration certificate does not replace suitability assessment for the smallest intended quantity.

Related forms

F-004, F-007