Reaffirmed 2024

NATIONAL FOREWORD

This Indian Standard (Part 2) (First Revision) which is identical with ISO 6145-2 : 2014 ‘Gas analysis - Preparation of calibration gas mixtures using dynamic methods - Part 2: Piston pumps’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the Industrial Gases Sectional Committee and approval of the Chemical Division Council.

This standard describes a method and system used for the preparation of calibration gas mixtures using piston pumps. The mixture composition and its associated uncertainty are based on calibration of the piston pumps by dimensional measurements. The calibration gas mixtures prepared using this method consist of two or more components, prepared from pure gases or other gas mixtures using gas-mixing pumps. Such gas-mixing pumps contain at least two piston pumps, each driven with a defined ratio of strokes, and appropriate accessories for gas feeding and mixture homogenization.

This standard, which was originally published in 2015, was identical with ISO 6145-2 : 2001. The first revision of this standard has been undertaken to align it with ISO 6145-2 : 2014.

In this revision, calculation of the composition in volume and amount-of-substance fractions from the displacement volumes of piston pumps has been incorporated.

This standard is applicable only to mixtures of gaseous or totally vaporized components including corrosive gases, as long as these components neither react with each other nor react with the wetted surfaces of the mixing pump. The use of gas mixtures as parent gases is covered as well. Multi- component gas mixtures and multi-step dilution procedures are included in this standard as they are considered to be special cases of the preparation of two-component mixtures. This Indian Standard is published in several parts. The other parts in this series are:

Part 1 Methods of calibration

Part 4 Continuous syringe injection method

Part 5 Capillary calibration devices

Part 6 Critical flow orifices

Part 7 Thermal mass-flow controllers

Part 8 Diffusion method

Part 9 Saturation method

Part 10 Permeation method

Part 11 Electrochemical generation

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appears referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.