Re: [ARSCLIST] New CD Report NIST

[Jerome Hartke <jhartke@xxxxxxxxxxxx>]

I believe that Kodak and TDK may have published information long ago, but
that was all based on BLER. Other than that, Google would be a good option.

Jerry

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Steven Smolian
> Sent: Monday, December 13, 2004 5:56 PM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] New CD Report NIST
>
> This is a question for Mr. Hartke:
>
> Apart from your own report on CD testing, can you suggest a readily
> available web source which discusses the same issues, preferably one which
> does not come from a professional testing service?
>
> Steven Smolian
>
> ----- Original Message -----
> From: "Jerome Hartke" <jhartke@xxxxxxxxxxxx>
> To: <ARSCLIST@xxxxxxxxxxxx>
> Sent: Monday, December 13, 2004 3:14 PM
> Subject: Re: [ARSCLIST] New CD Report NIST
>
>
> > As mentioned before, BLER alone gives misleading results for accelerated
> > aging as reported at http://www.mscience.com/longev.html
> >
> > Jerry
> > Media Sciences, Inc.
> >
> >> -----Original Message-----
> >> From: Association for Recorded Sound Discussion List
> >> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Joe_Iraci@xxxxxxxxx
> >> Sent: Monday, December 13, 2004 10:07 AM
> >> To: ARSCLIST@xxxxxxxxxxxx
> >> Subject: Re: [ARSCLIST] New CD Report NIST
> >>
> >> I have performed a similar study that will be published in Restaurator
> in
> >> early 2005 (I will pass on the reference to the list once it is
> >> published).
> >> Accelerated aging was performed on CDs, CD-Rs (various dye types),
> >> CD-RWs,
> >> DVDs, DVD-Rs, DVD-RWs.  Many (much more than the NIST study) different
> >> types from different manufacturers were tested.  Results were based on
> >> BLER
> >> changes.  Conclusion was that the CD-R with phythalocyanine dye
> >> outperformed all other disc formats.  A relative stability ranking of
> the
> >> various formats was produced.
> >>
> >> The goal of the study was to assist individuals in making choices when
> it
> >> comes to optical media.  Making a  lifetime prediction is time
> consuming,
> >> expensive, and usually contains a lot of uncertainty.  I believe a more
> >> practical approach is examining relative stabilities.  Any study that
> >> provides information on how this media reacts is useful.  Granted
> >> reactions
> >> are occurring at higher temperatures and there is no guarantee that
> those
> >> same reactions will occur at room temperature, but if you had to choose
> >> would you trust media that withstood harsh accelerated aging (80
> degrees
> >> Celsius and 85% relative humidity for intervals up to 84 days) and
> still
> >> had no E32 errors and low BLER or media that failed within the first 21
> >> days under these same conditions.
> >>
> >> Yes, there are other factors to consider like writing speed and
> >> compatibility issues, but the focus is on media stability in this case.
> >>
> >> In the above study, using either BLER or E32 errors would have led to
> the
> >> same conclusions.  BLER alone can sometimes be misleading, but
> generally
> >> not when it comes to monitoring degradation via accelerated aging.   As
> >> long as both are monitored I do not see a problem using BLER. This
> >> observation is based on the experience of aging and analyzing several
> >> hundred discs.  Same applies to PI errors for DVDs.
> >>
> >> Joe Iraci
> >> Senior Conservation Scientist
> >> Canadian Conservation Institute