Nitrogen generators for anoxic pest treatment

Jessie Firth <jessie.firth<-at->awm<.>gov<.>au> writes

>...  Firstly we want to know what purity or grade of nitrogen
>is required for 100% kill?  And secondly, there are two types of
>nitrogen generators available, membrane and chemical.  Does anyone
>have experience with either system?  We are asking for advice and
>peoples experience in terms of purity/grade of produced Nitrogen,
>portability, initial cost and ongoing maintenance costs.

As I understand it the variables for the desirable purity of the
nitrogen include the target pest, temperature, RH, and duration. I
have happily been using a PSA nitrogen generator for pest treatments
in the USA for about six years, and prior to that I was using
cylinders. The generator was supplied by vendors to bars/pubs, since
fizzy drinks are prepared with nitrogen and carbon dioxide; my unit
is not fitted for carbon dioxide. It is operated here for 2 to 7
weeks/year and I have not yet replaced the filters. I pass some
nitrogen through water to regulate RH. I monitor the object chamber
(usually Escal) for oxygen with a twenty year old portable analog
oxygen monitor and achieve 0.02% oxygen, and I reduce the time it
takes to achieve this level by including some Ageless Z-2000. My
duration at 0.02% oxygen, 45% RH, 20 deg C, is at least three weeks.

Hugh Glover
Williamstown Art Conservation Center


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                  Conservation DistList Instance 27:25
                 Distributed: Sunday, December 15, 2013
                       Message Id: cdl-27-25-002
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