scope:

This International Standard describes the principles of a saturation method for the continuous preparation of calibration gas mixtures, one of the components of which is readily condensable. An accuracy of 3% relative value may be obtained on the concentration, expressed as a pressure ratio. Readily condensable gases often exhibit very marked sorption phenomena;it is, therefore, difficult to prepare mixtures comprising such gases by static methods. Moreover, the use of high pressures precludes the achievement of concentrations close to the saturation limit during the use of the mixture at atmosphere pressure. In these cases, recourse should be made to the method described in this International Standard.