For all parameters, this set of specifications comprises a proposal for the number of stoppers to be tested (incremental sample); an acceptable quality level and, for certain parameters: nominal value or values; specification limits (or tolerances).
For cork stoppers for still wines, and for certain parameters, the concept of a range is introduced, with 3 decreasing levels of requirements: upper range; standard range; entry level.
It is, therefore, up to the consumer to specify, for each batch of cork stoppers ordered, what their needs are based on these three specification levels (or ranges).
It is also up to each supplier, besides a commercial reference for each batch of cork stoppers, to define which range applies in terms of the requirements in ISO 16420:2013.
The sampling method, as well as the possible repetitions of incremental samples are defined by the sampling standard (currently being drafted) or defined jointly by the consumer and the supplier.
The stoppers tested shall comply with the requirements of ISO 9727.