BS EN ISO 6145-7:2018 Gas analysis. Preparation of calibration gas mixtures using dynamic methods. Thermal mass-flow controllers

BS EN ISO 6145-7:2018

Gas analysis. Preparation of calibration gas mixtures using dynamic methods. Thermal mass-flow controllers

Status : Current   Published : January 2019

Format
PDF

Format
HARDCOPY



What is this standard about?

ISO 6145 is a series of documents dealing with various dynamic methods used for the preparation of calibration gas mixtures. This document specifies a method for continuous preparation of calibration gas mixtures, from nominally pure gases or gas mixtures by use of thermal mass-flow controllers. The method is applicable to preparation of mixtures of non-reacting species, i.e. those which do not react with any material of construction of the flow path in the thermal mass-flow controller or the ancillary equipment.

If this method is employed for preparation of calibration gas mixtures the optimum performance is as follows: the relative expanded measurement uncertainty U, obtained by multiplying the standard uncertainty by a coverage factor k = 2, is not greater than 2 %.

If pre-mixed gases are used instead of pure gases, mole fractions below 10−6 can be obtained. The measurement of mass flow is not absolute and the flow controller requires independent calibration.

The merits of the method are that a large quantity of the calibration gas mixture can be prepared on a continuous basis and that multi-component mixtures can be prepared as readily as binary mixtures if the appropriate number of thermal mass-flow controllers is utilized.

NOTE Gas blending systems, based upon thermal mass-flow controllers, and some including the facility of computerization and automatic control, are commercially available.




Standard NumberBS EN ISO 6145-7:2018
TitleGas analysis. Preparation of calibration gas mixtures using dynamic methods. Thermal mass-flow controllers
StatusCurrent
Publication Date04 January 2019
Normative References(Required to achieve compliance to this standard)ISO 6145-1, ISO 7504, ISO 19229, ISO 6143, ISO 12963
Informative References(Provided for Information)GUM:1995, ISO 6142-1, ISO/IEC Guide 98-3:2008, ISO 14511:2001
ReplacesBS EN ISO 6145-7:2010
International RelationshipsEN ISO 6145-7:2018,ISO 6145-7:2018
Draft Superseded By17/30365496 DC
DescriptorsGases, Gas analysis, Flow regulators, Mixtures, Flow control, Volumetric analysis, Mass, Calibration, Thermal measurement, Control samples, Chemical composition
ICS71.040.40
Title in FrenchAnalyse des gaz. Préparation des mélanges de gaz pour étalonnage à l'aide de méthodes dynamiques Régulateurs thermiques de débit massique
Title in GermanGasanalyse. Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-volumetrischen Verfahren Thermische Massendurchflussregler
CommitteePTI/15
ISBN978 0 580 51170 7
PublisherBSI
FormatA4
DeliveryYes
Pages22
File Size747 KB
Price£130.00


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