[GLLUG] CD-R media and temperature

[Lachniet, Mark]

> I tend to burn cds in batches. One for at home, one for the 
> car, one for 
>   at work, etc. I have noticed that the ones that I carry in 
> the car go 
> "bad" very quickly. The others of the same generate continue to play 
> without problems for years.

Certainly the temperature changes of a car that is outside is not good
for the media.  Based on my very limited understanding, the dye layer
that is attached to the disc plastic can come free and cause problems.
It may be as simple as that.

From: http://www.osta.org/technology/cdqa13.htm

"to calculate disc life spans within some practical timeframe blank
media manufacturers do conduct accelerated age testing by subjecting
samples of their discs to environments much beyond those experienced
under normal storage conditions. Generally speaking, only the effects of
varying temperature and humidity are considered. These test results are
then used to predict how long a disc will remain readable under more
normal storage conditions. Since questionable testing and measurement
procedures can seriously impact upon and compromise these estimates
several international standards have been developed which specify
procedures to be used conducting accelerated testing and analyzing the
resulting data from prerecorded (pressed) and recordable CDs:

ISO 18921:2002, Imaging materials - Compact discs (CD-ROM) - method for
estimating the life expectancy based on the effects of temperature and
relative humidity

ISO 18927:2002, Imaging materials - Recordable compact disc systems -
method for estimating the life expectancy based on the effects of
temperature and relative humidity"