ISO 16664:2004 PDF

ISO 16664:2004 describes factors that may influence the composition of pure gases and homogeneous gas mixtures used for calibration purposes. ISO 16664:2004 only applies to gases or gas mixtures that are within the "utilization period", and it pays special attention to storage of calibration gas cylinders; calibration gas withdrawal from cylinders; transfer of calibration gas from cylinders to the point of calibration. ISO 16664:2004 also outlines a method of assessing the stability for a gas mixture, and takes into account the gas composition uncertainty given on the certificate and the users measurement uncertainty.