A.9 Sampling and measuring methods
A.9.1
To ensure compliance of the prepackages with the stated requirements at all times, the packer should conduct sufficient sampling of the running production to obtain data that enable the packer to decide whether the production process is in control. Records of the sampling and the results of measurement should be kept for a sufficient period to be evaluated by the designated body.
A.9.2
When determining the sampling criteria, consideration should be taken of the standard deviation and filling rate of the filling process. A sample should be taken after each manual adjustment to correct a filling process.
A.9.3
Where products are measured together with the packaging material (i.e. complete prepackage), the weight of the packaging material should be determined on a regular basis to determine whether it is sufficiently consistent to allow an average tare weight to be used. The requirements given in OIML R 87:2016 for determining the average tare weight and acceptability for use should be used as a minimum. Where the use of the average tare weight is not suitable because of a large deviation in the weight of individual packaging materials, the mass of each individual packing material should be taken into consideration.
A.9.4
When the quantity of liquid is determined by gravimetric means, the density of every batch of liquid product should be determined by a method that is suitably accurate to ensure that the overall uncertainty of measurement of the test method is not exceeded.
A.9.5
When calculating the volume from the mass of a liquid using the determined density, the requirements for air buoyancy and density corrections in OIML R 87:2016 should be used.
A.9.6
Product quantity control charts that are manually completed, automated systems connected to weighing and measuring instruments and network connected automated systems are accepted. Software in automated systems must be validated (see A.9.7).
A.9.7
Software and systems used in production control should be secured and validated to ensure that they fulfil their intended purpose, and that they are accessible to, and may be modified by, designated personnel only.