Re: Glass dilectric constant

Tesla List wrote:
> Original Poster: kc1-at-ime-dot-net
> I've seen plenty of different dilectric constant values for glass... anyone
> know if the value of, say, wine bottle glass?  Closer to five or ten?

My latest book finding, M.Khalifa's "High voltage engineering,
Theory and practise", lists following glass types:

Material         epsilon-r   tan phi (25C, 1Mhz) 
Quartz glass     3.8         5e-4
Lead glass       9           ?
Soda-lime glass  7           0.01
Glass ceramic    5-7         0.001 - 0.1

Normal wine bottle most propably is soda-lime glass. Even though the
table lists "exact" values, I wouldn't expect to get the same
dielectric-constant with "unknown" glass type. Besides that, the
bottle wall thickness will not be a constant. So it is easier to
test the capasitance per bottle, than to try to calculate anything.

The interesting one is the quartz glass! The dissipation factor is
very reasonable. The downside is that quartz glass is expensive,
and usually of optical quality (VERY expensive). 

  Kristian Ukkonen.