ДСТУ EN ISO 6145-6:2022 Анализ газов. Приготовление калибровочных газовых смесей динамическими методами. Часть 6. Сопла критической утечки (EN ISO 6145-6:2017, IDT; ISO 6145-6:2017, IDT)

ДСТУ EN ISO 6145-6:2022
(EN ISO 6145-6:2017, IDT; ISO 6145-6:2017, IDT)

Аналіз газів. Готування калібрувальних газових сумішей динамічними методами. Частина 6. Сопла критичного витікання

 
   
 
 
     
Не є офіційним виданням.
Офіційне видання розповсюджує національний орган стандартизації
(ДП «УкрНДНЦ» http://uas.gov.ua)

Contents

European foreword

Foreword

1 Scope

2 Normative references

3 Terms and definitions

4 Symbols

5 Principle

6 Calculation of mass flow rate and volume flow rate

6.1 General

6.2 Calculation under ideal conditions

6.2.1 Calculation of mass flow rate

6.2.2 Calculation of volume flow rates

6.3 Calculation of mass flow rate using flow calibration with pure nitrogen

6.4 Flow rate uncertainty calculation

6.4.1 General

6.4.2 Sources of uncertainty

6.4.3 Uncertainty estimation

7 Calculation of amount of substance fraction and volume fraction and associated uncertainty evaluation

7.1 General

7.2 Amount of substance fraction calculation and associated uncertainty

7.2.1 Case of gases with purity ≥ 99,99 %

7.2.2 Case of pre-mixtures

7.3 Remarks about uncertainty for the amount fraction

8 Application to the preparation of gas mixtures

8.1 Example of a mixing system

8.2 Conditions of operation

9 Calibration and verification

9.1 General

9.2 Calibration of the mixing system in the flow rate

9.3 Calibration of the mixing system with gas mixtures for a specific gas and concentration

9.4 Verification of the mixing system

Annex A (informative) Example of calculation of isentropic coefficient, viscosity and critical flow coefficient

A.1 Example of calculation of the isentropic coefficient

A.2 Example of calculation of the dynamic viscosity

A.3 Example of calculation of critical flow coefficient Cr

Annex B (informative) Calculation of mass and volume flow rates under real conditions

B.1 Calculation of the mass flow rate

B.2 Calculation of the volume flow rate

Annex C (informative) Example of flow calculation for toroidal critical flow orifices under ideal and real conditions

Annex D (informative) Calculation of mass flow rate using flow calibration with pure nitrogen: examples

D.1 General

D.2 Example 1: Calculation of the mass flow rate of pure oxygen

D.3 Example 2: Calculation of mass flow rate of pure hydrogen

Bibliography