Re: NEC-LIST: material question

 From a google search, see
http://www.engnetglobal.com/search/brands.asp?brandid=4021, which says
it's "cast acrylic sheet." Be careful: any given brand name plastic
typically comes in many different variations with varying mechanical and
electrical properties. That said, from "Reference Data for Engineers,"
polymethyl methacrylate is listed with dielectric constant of 2.76 at
1MHz and 2.60 at 3GHz, and a not-so-wonderful dissipation factor of
0.014 and 0.0057 at those two frequencies respectively. See
http://monographs.iarc.fr/htdocs/monographs/vol19/methylmethacrylate.html
for, among other things, a list of synonyms for polymethyl
methacrylate--the list includes perspex. Ideally, you'd get better info
from the manufacturer of the particular plastic you are considering.

Cheers,
Tom

zvi frank wrote:

>Does anyone know the electrical properties of perspex ,dielectric constant
>and loss tangent? What is the chemical name for perspex?
>
>zVi
>
>
>

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