This Document presents guidelines taken to calibrate volumetric instruments such as piston pipettes, hand dispensers (according to ISO 8655 / DKD-R 8-1), glassware adjusted as to deliver “Ex”, such as Bulb pipettes (according to ISO 648), Graduated pipettes (according to ISO 835), Burettes for liquids (according to ISO 385), glassware adjusted as to contain “In”, such as volumetric flasks (according to ISO 1042), graduated cylinders and mixing cylinders (according to ISO 4788), according to the requirements of ISO 4787.