"This is the most varying specification of a SPD, as there are no standards
for measuring Joule Rating.  The commonly used definition of Joule Rating is
the amount of energy the SPD can absorb before it becomes damaged.  It doesn
't quantify a level of protection to the electronic equipment that is
plugged into the SPD."  Source:
http://www.heco.com/CDA/default/0,1999,TCID%253D2%2526EmbedCID%253D0%2526CCI
D%253D4295%2526LCID%253D4281%2526CTYP%253DARTC,00.html

As there is no standard for measuring joules, the manufacturers can, and
often do, fudge the rating.  Ian is right about the higher rating the
better.

Another descriptive article regarding how to compare UPS's:
http://www.bestbuy.com/ComputersPeripherals/Desktops/hr/hr6SurgeProtectorsAn
dUPS.asp

Fred Nielson

-----Original Message-----
>Just one last question concerning a battery back-up.  What is a joule
rating?
>Susan Hays

>Joule is supposedly the amount or quantity of energy a device puts out; so
a higher number theoretically better.  But consider the info here:
http://www.currenttechnology.com/newsletters/winterpg5.htm
<Ian Carmichael>

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