From 14 until 16 February 2007 NEN and ISO/TC 158 jointly organised GAS2007 in the World Trade Centre in Rotterdam, the Netherlands. ISO/TC 158 is the technical committee on analysis of gases, which mainly produces standards on preparation, handling and precision of calibration gases. It was the fourth time that this international, three-day congress was organised. This time the organization surpassed itself and its expectations with 250 participants, nearly 60 lectures en 25 exhibition booths by equipment and calibration gas manufacturers at the parallel exhibition.......