Article: Q&A with Geoff Collis about the pack permeability proficiency scheme

Smithers Pira expert Geoff Collis provides insight into the process, and what it means for clients.

Who is the proficiency scheme designed for?

Proficiency schemes are generally aimed at laboratories seeking to demonstrate their data accuracy to customers and accreditation bodies. This is particularly relevant to permeability testing, where there are a number of testing techniques being developed and no common reference value.

How does the scheme work?

Participating clients are provided with two sets of 4 replicate packs which they test/evaluate following their standard laboratory procedure. The client completes an electronic results sheet which is returned to Smithers Pira.

Subscribers can choose to take samples for Water Vapour and/or Oxygen Permeability, for testing at 23⁰C, 50%rh and 38⁰C, 90%rh.

What happens to the results?

The results from all the participating laboratories are collated and included in a statistical review, which is then issued as a report to each client. The values are assessed for bias, stability and repeatability.

Each laboratory is assigned a unique number to maintain client confidentiality. Performance data is reported anonymously to the wider group.

What methods can I use to perform the testing?

Any documented method may be used; examples include:

  • WVTR: ASTM F1249 (infrared sensor method), USP 671 (gravimetric method)
  • OxPerm: ASTM F1307 (coulometric sensor method), ASTM F2714 (fluorescent decay method)

Details of the equipment/method used must be provided when returning the test results.

What is the time interval between proficiency services?

The service operates on a six monthly interval. The results of samples sent out to clients in April should be returned by the following September and a report issued in October.

Is there a similar service specifically for film permeability?

Yes, we have a long running film proficiency service.

How do I apply to join the scheme?

You can register your interest via the downloadable form on our Permeability Proficiency - Pack page.