3.4.2 Materials and fabrication

The materials of construction and the pressure rating of the prover should be compatible with the measuring systems to be verified/calibrated and the test liquids. The prover should be thermally insulated for the required duty and operational conditions. If separation of prover components is necessary (e.g. for transportation), the correct reassembly of the components shall be ensured by an appropriate reconstruction and by a recalibration of the base volume. Internal coating of the prover with the correct material should be used to reduce corrosion and wear.