scope:

ISO 6145 comprises a series of International Standards dealingwith various dynamic methods used for the preparation ofcalibration gas mixtures. This part of ISO 6145 describes a methodand preparation system using piston pumps. The mixture compositionand its associated uncertainty are based on calibration of thepiston pumps by dimensional measurements. The calibration gasmixtures prepared using this method consist of two or morecomponents, prepared from pure gases or other gas mixtures usinggas-mixing pumps. Such gas-mixing pumps contain at least two pistonpumps, each driven with a defined ratio of strokes, and appropriateaccessories for gas feeding and mixture homogenization.