For storage and transport of conditioned or sampled tubes, long-term storage caps fitted with PTFE ferrules must be used to ensure an effective seal is achieved and minimise loss of sample/ingress onto the tube. Typically, brass Swagelok style caps are used but aluminium caps are available as an alternative.
- Multi-use product: Can be used for short-term and long-term storage, and transport
- Recommended by international standard methods such as US EPA Method TO-17, ASTM D6196 and EN ISO 16017
- Independently validated for up to 27 months
- Caps meet a stringent cleanliness specification and tight manufacturing tolerances
- Removable/replaceable ferrule to allow effective cleaning and prevent cross-contamination
Aluminium caps are lighter, and are typically used during personal diffusive monitoring to close-off the non-sampling end of the tube and so prevent contamination/loss of sample. Being light, they also prevent unconscious changes in the behaviour of those being monitored.
Caps are compatible with all industry-standard sorbent tubes: (6.35 mm o.d.) and 6 mm o.d. tubes (including DAAMS and TD Mini-tubes).
For storage, two caps are required per tube. For passive sampling, one cap is required for the non-sampling end, while a diffusive sampling cap is used on the sampling end.
Long-term (brass) storage caps ship as standard with tubes purchased pre-conditioned from Markes. Ferrules should be replaced routinely or when switching applications. To prevent overtightening of long-term storage caps, Markes recommends the CapLok tool.