Тезис

ISO 6145-7:2009 specifies a method for continuous production of calibration gas mixtures, containing two or more components, from pure gases or other gas mixtures by use of commercially available thermal mass-flow controllers.

If this method is employed for the preparation of calibration gas mixtures, the optimum performance is as follows: the relative expanded uncertainty of measurement, U, obtained by multiplying the combined 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 gas mixture can be prepared on a continuous basis and that multicomponent mixtures can be prepared as readily as binary mixtures if the appropriate number of thermal mass-flow controllers is utilized.


Общая информация 

  • Текущий статус
     :  Withdrawn
    Дата публикации
     : 2009-04
  • Версия
     : 2
  • Технический комитет
     : ISO/TC 158 Analysis of gases
  • ICS
     :
    71.040.40 Chemical analysis

Жизненный цикл


Появились вопросы?

Ознакомьтесь с FAQ

Работа с клиентами
+41 22 749 08 88

Часы работы:
Понедельник – пятница: 09:00-12:00, 14:00-17:00 (UTC+1)

Будьте в курсе актуальных новостей ИСО

Подписывайтесь на наши новости, обзоры, а также на информацию о продуктах.

  2. Интернет-магазин
  3. Каталог стандартов
  4. ТК
  5. ISO/TC 158
  6. ISO 6145-7:2009