The new chapter was published in July 2021 and entered into force on January 1, 2022.

During calibration, a relationship is established between the known values of the certified test weights and the values measured by the balance. Chapter 2.1.7 states that “... the instruments must be periodically calibrated [...] by the user or by a suitable competent body”. There are three requirements established in the Ph.Eur. (2.1.17):

• The calibration must establish the traceability of the measurement results in the international SI system.
• The results of the calibration must be associated with the uncertainty of measurement.
• It is recommended to perform the "asfound" calibration (as found) before any maintenance operation and then a second "as left" calibration (as left).

The calibration of an instrument according to the Eu.Ph. (2.1.7) must be performed by an accredited center. The Gibertini 17025 calibration service guarantees competence through its LAT094 accreditation.

A test load not exceeding 5% of the maximum capacity of the balance, or at least equal to 100 mg, is used to check the repeatability. The weight is placed 10 times on the weighing pan, zeroing the instrument before each measurement.

• Repeatability is satisfactory if 2 times the standard deviation or deviation (s) divided by the minimum net weight defined by the laboratory is not greater than 0.10%.
• In cases where the standard deviation (s) is less than 0.41 × d (where d is the scale unit of format), s is replaced by 0.41 × d.

Per il calcolo della sensibilità, viene posto un peso certificato compreso tra il 5% e il 100% della portata della bilancia e viene rilevata l'indicazione.

• Sensitivity is satisfactory if the difference between the indication and the conventional mass of the sample is not more than 0.05%.

The smallest possible sample weight on a laboratory balance is related to the minimum weight (R), which is 2000 times the standard deviation. Therefore, if the calculated standard deviation turns out to be s = 0.25 mg, the minimum weight will be R = 500 mg.

• If the repeatability is less than 0.41 x d, the Ph.Eur. requires the minimum weight (R) to be replaced with 820 × d
• Therefore the minimum possible weight (Rmin) cannot be less than 820 × d

Below is the table of the minimum possible weights for the Crystal analytical balance