The descriptive markings shall be indelible and of a size, shape and clarity to enable legibility under normal conditions of use of the filling instrument. They shall be grouped together in a clearly visible place on the filling instrument, either on a data plate fixed to the instrument or on the filling instrument itself.

• Where the markings are placed on a data plate, it shall be possible to seal the plate bearing the markings. Where they are marked on the filling instrument itself, it shall not be possible to remove them without destroying them.

• The descriptive markings may be shown on a programmable display which is controlled by software. In this case, means shall be provided for any access to reprogramming of the markings to be automatically and non-erasably recorded, e.g. by traceable access software. When a programmable display is used, the plate on the instrument shall bear at least the following markings:

  • type and designation of the instrument,

  • name or identification mark of the manufacturer,

  • pattern approval number,

  • electrical supply voltage,

  • electrical supply frequency,

  • pneumatic pressure.