NF EN ISO 6145-6

NF EN ISO 6145-6

August 2017
Standard Current

Gas analysis - Preparation of calibration gas mixtures using dynamic methods - Part 6 : critical flow orifices

ISO 6145-6:2017 specifies a method for the dynamic preparation of calibration gas mixtures containing at least two gases (usually one of them is a complementary gas) from pure gases or gas pre-mixtures using critical flow orifices systems. The method applies principally to the preparation of mixtures of non-reactive gases that do not react with any of the materials forming the gas circuit inside the critical flow orifices system or auxiliary equipment. It has the merit of allowing multi-component mixtures to be prepared as readily as binary mixtures if an appropriate number of critical flow orifices are used. By selecting appropriate combinations of critical flow orifices, a dilution ratio of 1 × 104 is achievable. Although it is more particularly applicable to the preparation of gas mixtures at atmospheric pressure, the method also offers the possibility of preparing calibration gas mixtures at pressures greater than atmospheric. The upstream pressure will need to be at least two times higher than downstream pressure. The range of flow rates covered by this document extends from 1 ml/min to 10 l/min.

View the extract
Main informations

Collections

National standards and national normative documents

Publication date

August 2017

Number of pages

31 p.

Reference

NF EN ISO 6145-6

ICS Codes

71.040.40   Chemical analysis

Classification index

X20-205-6

Print number

1

International kinship

European kinship

EN ISO 6145-6:2017
Sumary
Gas analysis - Preparation of calibration gas mixtures using dynamic methods - Part 6 : critical flow orifices

ISO 6145-6:2017 specifies a method for the dynamic preparation of calibration gas mixtures containing at least two gases (usually one of them is a complementary gas) from pure gases or gas pre-mixtures using critical flow orifices systems.

The method applies principally to the preparation of mixtures of non-reactive gases that do not react with any of the materials forming the gas circuit inside the critical flow orifices system or auxiliary equipment. It has the merit of allowing multi-component mixtures to be prepared as readily as binary mixtures if an appropriate number of critical flow orifices are used.

By selecting appropriate combinations of critical flow orifices, a dilution ratio of 1 × 104 is achievable.

Although it is more particularly applicable to the preparation of gas mixtures at atmospheric pressure, the method also offers the possibility of preparing calibration gas mixtures at pressures greater than atmospheric. The upstream pressure will need to be at least two times higher than downstream pressure.

The range of flow rates covered by this document extends from 1 ml/min to 10 l/min.

Replaced standards (1)
NF EN ISO 6145-6
December 2008
Standard Cancelled
Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 6 : critical orifices

Le présent document spécifie une méthode de préparation en continu de mélanges de gaz pour étalonnage, contenant au moins deux constituants, à partir de gaz purs ou d'autres mélanges de gaz à l'aide de systèmes à orifices critiques. Cette méthode, particulièrement applicable à la préparation de mélanges de gaz à pression atmosphérique, offre également la possibilité de préparer des mélanges de gaz pour étalonnage à des pressions supérieures à la pression atmosphérique. Ce document fait partie d'une série de normes présentant différentes méthodes volumétriques dynamiques, utilisées pour préparer des mélanges de gaz pour étalonnage.

Table of contents
View the extract
  • Avant-propos
  • 1
  • 2 Références normatives
  • 3 Termes et définitions
  • 4 Symboles
  • 5 Principe
  • 6 Calcul du débit massique et du débit volumique
  • 7 Calcul de la fraction molaire et de la fraction volumique et évaluation de l'incertitude associée
  • 8 Application à la préparation des mélanges de gaz
  • 9 Étalonnage et vérification
  • Annexe A (informative) Exemple de calcul du coefficient isentropique, de la viscosité et du coefficient critique
  • Annexe B (informative) Calcul du débit massique et du débit volumique dans des conditions réelles
  • Annexe Annexe C (informative) Exemple de calcul de débit pour des orifices critiques à col toroïdal dans des conditions idéales et réelles
  • Annexe D (informative) Calcul du débit massique en réalisant l'étalonnage du débit avec de l'azote pur: exemples
  • Bibliographie
What is the Redline format?
The Redline + service - standards comparator allows you to easily and simply identify major changes between the current standard and its last canceled version.

At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula.
At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula

The Redlines + service is offered to you on the collection of French standards in force, in French language and in HTML and PDF format.

For an overview of the service, click on View a standard in redline format
Need to identify, monitor and decipher standards?

COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.

Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!

Request your free, no-obligation live demo

I discover COBAZ