Pharmacopoeia Certificates in Laboratory Weighing

Typically, a calibration certificate indicates measurements for repeatability, eccentricity and error of indication. The ACC provides results for all these parameters, as well as:

• Measurement uncertainty
• As Found/As Left performance of the weighing instrument

The ACC indicates the measurement uncertainty for error of indication test points. The indication of measurement uncertainty in a calibration certificate is stipulated in the various Pharmacopoeias. In addition, the ACC always indicates the As Found/As Left test results.

Note that ACC does not provide specific assessments for repeatability and accuracy, including a statement of compliance with the various Pharmacopoeia Chapters. This is covered by the Certificate Pharmacopoeias.

There is an official definition: An analytical balance starts with a readability of 0.1 mg or smaller.

However, the framework of the pharmacopoeia regulations considers devices that are used for analytical purposes. If you use a precision balance for analytical purposes (which is rare but might occur) then the precision balance would also have to follow USP, JP, and European Pharmacopoeia regulations.

For example, General Chapter 2.1.7 stipulates that specific performance checks must be carried out in between calibrations. While calibrations are usually performed annually or in intervals of three to six months, performance checks are typically performed more often, depending on the risk of the application and the quality requirements of the user. However, it is still left up to each company to define appropriate intervals for calibration and performance checks based on their own quality considerations and the risk of their specific applications. GWP^® Verification fills this gap and provides a clear risk-based test strategy for suggested calibration frequencies, individual routine tests, test weights, test weight classes, and test weight recalibration intervals.