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 | | From: | Don A. Gilmore | | Subject: | Re: Resistive sheet | | Date: | Tue, 04 Jan 2005 02:25:38 GMT |
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 | wrote in message
news:1104778786.321726.203130@z14g2000cwz.googlegroups.com...
> Don,
> Your previous comment (Jan 3, 8:32 am) implies you are interested in
> current flow that is due to electrical boundary conditions on opposite
> sides of the sheet. Is that correct?
>
> Your original post said.."Here are the corresponding
> resistivities for some nominal inch thicknesses:
>
> .031 in ---> 300 ohm-m
> .062 in ---> 150 ohm-m
> .125 in ---> 75 ohm-m
> .188 in ---> 50 ohm-m"
>
> I may have mis-interpreted this as meaning you are interested in
> current flow between electrode areas separated in the plane of the
> sheet. The resistance one would measure perpendicular to such a sheet
> will depend on the size and lateral displacement of the electrodes
> relative to the thickness of the sheet.
>
> Perhaps your question was much simpler: if I had a material with a
> bulk resistivity of 75 ohm-m and gave you a piece in the shape of a
> .125" thick sheet is that all you want?
> If so, how large a sheet? Flexible or rigid? Durable?
Yes, that's all I want. I would prefer sheets as large as possible...in
roll form would be great. It doesn't have to be super-flexible, but I don't
want it brittle like glass either. It will be applied to a slightly
irregular surface, but generally planar...maybe sort of like a large
airplane wing. It will not be subjected to much abuse, but it might be
exposed to normal outdoor temperatures.
So far I'm leaning toward some conductive plastic sheet material that
McMaster-Carr carries. But only because it's all I've found yet (and it
only comes in 12" x 12" sample sheets". That's why I was wondering if one
of you clever guys might have heard of something else that I missed.
Don
Kansas City
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| | From: | Robert Baer | | Subject: | Re: Resistive sheet | | Date: | Tue, 04 Jan 2005 08:51:04 GMT |
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| "Don A. Gilmore" wrote:
>
> wrote in message
> news:1104778786.321726.203130@z14g2000cwz.googlegroups.com...
> > Don,
> > Your previous comment (Jan 3, 8:32 am) implies you are interested in
> > current flow that is due to electrical boundary conditions on opposite
> > sides of the sheet. Is that correct?
> >
> > Your original post said.."Here are the corresponding
> > resistivities for some nominal inch thicknesses:
> >
> > .031 in ---> 300 ohm-m
> > .062 in ---> 150 ohm-m
> > .125 in ---> 75 ohm-m
> > .188 in ---> 50 ohm-m"
> >
> > I may have mis-interpreted this as meaning you are interested in
> > current flow between electrode areas separated in the plane of the
> > sheet. The resistance one would measure perpendicular to such a sheet
> > will depend on the size and lateral displacement of the electrodes
> > relative to the thickness of the sheet.
> >
> > Perhaps your question was much simpler: if I had a material with a
> > bulk resistivity of 75 ohm-m and gave you a piece in the shape of a
> > .125" thick sheet is that all you want?
> > If so, how large a sheet? Flexible or rigid? Durable?
>
> Yes, that's all I want. I would prefer sheets as large as possible...in
> roll form would be great. It doesn't have to be super-flexible, but I don't
> want it brittle like glass either. It will be applied to a slightly
> irregular surface, but generally planar...maybe sort of like a large
> airplane wing. It will not be subjected to much abuse, but it might be
> exposed to normal outdoor temperatures.
>
> So far I'm leaning toward some conductive plastic sheet material that
> McMaster-Carr carries. But only because it's all I've found yet (and it
> only comes in 12" x 12" sample sheets". That's why I was wondering if one
> of you clever guys might have heard of something else that I missed.
>
> Don
> Kansas City
In that case, try the conductive anti-static foam sheets (24 inch by
12 inch by 0.25 thick) that Jameco carries; part 13864 for $9.29 ea or
$8.35 each @ 5. They roll it up for shipping.
Measured resistance across diagonal with probes close to the corners,
is about 8K.
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| | From: | John Fields | | Subject: | Re: Resistive sheet | | Date: | Tue, 04 Jan 2005 11:56:41 -0600 |
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| On Tue, 04 Jan 2005 02:25:38 GMT, "Don A. Gilmore"
wrote:
> wrote in message
>news:1104778786.321726.203130@z14g2000cwz.googlegroups.com...
>> Don,
>> Your previous comment (Jan 3, 8:32 am) implies you are interested in
>> current flow that is due to electrical boundary conditions on opposite
>> sides of the sheet. Is that correct?
>>
>> Your original post said.."Here are the corresponding
>> resistivities for some nominal inch thicknesses:
>>
>> .031 in ---> 300 ohm-m
>> .062 in ---> 150 ohm-m
>> .125 in ---> 75 ohm-m
>> .188 in ---> 50 ohm-m"
>>
>> I may have mis-interpreted this as meaning you are interested in
>> current flow between electrode areas separated in the plane of the
>> sheet. The resistance one would measure perpendicular to such a sheet
>> will depend on the size and lateral displacement of the electrodes
>> relative to the thickness of the sheet.
>>
>> Perhaps your question was much simpler: if I had a material with a
>> bulk resistivity of 75 ohm-m and gave you a piece in the shape of a
>> .125" thick sheet is that all you want?
>> If so, how large a sheet? Flexible or rigid? Durable?
>
>
>Yes, that's all I want. I would prefer sheets as large as possible...in
>roll form would be great. It doesn't have to be super-flexible, but I don't
>want it brittle like glass either. It will be applied to a slightly
>irregular surface, but generally planar...maybe sort of like a large
>airplane wing. It will not be subjected to much abuse, but it might be
>exposed to normal outdoor temperatures.
>
>So far I'm leaning toward some conductive plastic sheet material that
>McMaster-Carr carries. But only because it's all I've found yet (and it
>only comes in 12" x 12" sample sheets". That's why I was wondering if one
>of you clever guys might have heard of something else that I missed.
---
You might want to try:
http://www.advsys.com.au/downloads/cuming%20catalogue.pdf
In particular, Technical Bulletin 320-8 on page 67.
Also, Series Number 26200 at:
http://www.right-tape.com/html/prod_silicone_rubber.html#photo6
Also there are a lot of hits you might want to check out at:
http://www.google.com/search?q=electrically+conductive+rubber+sheet&hl=en&lr=&start=20&sa=N
--
John Fields
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| | From: | Don A. Gilmore | | Subject: | Re: Resistive sheet | | Date: | Wed, 5 Jan 2005 13:22:58 -0600 |
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| "John Fields" wrote in message
news:n3llt0924ghrj7i8gl770s51npspg9tsnj@4ax.com...
> On Tue, 04 Jan 2005 02:25:38 GMT, "Don A. Gilmore"
> >Yes, that's all I want. I would prefer sheets as large as possible...in
> >roll form would be great. It doesn't have to be super-flexible, but I
don't
> >want it brittle like glass either. It will be applied to a slightly
> >irregular surface, but generally planar...maybe sort of like a large
> >airplane wing. It will not be subjected to much abuse, but it might be
> >exposed to normal outdoor temperatures.
> >
> >So far I'm leaning toward some conductive plastic sheet material that
> >McMaster-Carr carries. But only because it's all I've found yet (and it
> >only comes in 12" x 12" sample sheets". That's why I was wondering if
one
> >of you clever guys might have heard of something else that I missed.
>
> ---
> You might want to try:
>
> http://www.advsys.com.au/downloads/cuming%20catalogue.pdf
>
> In particular, Technical Bulletin 320-8 on page 67.
>
>
> Also, Series Number 26200 at:
>
> http://www.right-tape.com/html/prod_silicone_rubber.html#photo6
>
>
> Also there are a lot of hits you might want to check out at:
>
>
http://www.google.com/search?q=electrically+conductive+rubber+sheet&hl=en&lr=&start=20&sa=N
Great. Thanks John. The silicone is particularly intriguing.
Don
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