Division 9.3.2.4 Sample storage media
United Kingdom
In the case of bag sampling, gas volumes shall be stored in sufficiently clean containers that minimally off-gas or allow permeation of gases. Good engineering judgment shall be used to determine acceptable thresholds of storage media cleanliness and permeation. To clean a container, it may be repeatedly purged and evacuated and may be heated. A flexible container (such as a bag) within a temperature-controlled environment, or a temperature controlled rigid container that is initially evacuated or has a volume that can be displaced, such as a piston and cylinder arrangement, shall be used. Containers meeting the specifications in the following Table 6.6 shall be used.
Table 6.6
Gaseous Batch Sampling Container Materials
| As long as aqueous condensation in storage container is prevented. | |
| Up to 313 K (40 °C). | |
| Up to 475 K (202 °C). | |
| At 464 ± 11 K (191 ± 11 °C). | |
| CO, CO2, O2, CH4, C2H6, C3H8, NO, NO2 f1 | polyvinyl fluoride (PVF)f2 for example TedlarTM, polyvinylidene fluoride for example KynarTM, polytetrafluoroethylenef3 for example TeflonTM, or stainless steel |
| HC | polytetrafluoroethylenef4 or stainless steel |
Annotations
Footnotes
- f1
-
As long as aqueous condensation in storage container is prevented.
- f2
-
Up to 313 K (40 °C).
- f3
-
Up to 475 K (202 °C).
- f4
-
At 464 ± 11 K (191 ± 11 °C).