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Old August 11th 03, 01:47 AM
Tom Del Rosso
 
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Watson A.Name - 'Watt Sun' wrote:

I used to be able to do that with the nickle plated antistatic bags
that parts came in back in 1980. The ohmmeter would measure several
hundred ohms. But nowadays all I can measure is an open. I just
tried it again, measured open even on the 200M range.


Yeah, it's been like that for at least 15 years. Anti-static work mats
aren't conductive either. So what principle do they use?

--
-Reply in group, but if emailing please add two more zeros and delete
the obvious-


  #212   Report Post  
Old August 11th 03, 03:26 AM
Sir Charles W. Shults III
 
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Actually, they ARE supposed to be conductive- at least to the tune of about
a megohm. In any operation that is serious about antistatic procedures, the
mats, wrist straps, and other equipment are to be tested periodically. Most
testers show if a mat reads open right away.
If you have mats or other equipment that read open, then you have found
defective hardware. Trash it.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip


  #213   Report Post  
Old August 11th 03, 03:26 AM
Sir Charles W. Shults III
 
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Actually, they ARE supposed to be conductive- at least to the tune of about
a megohm. In any operation that is serious about antistatic procedures, the
mats, wrist straps, and other equipment are to be tested periodically. Most
testers show if a mat reads open right away.
If you have mats or other equipment that read open, then you have found
defective hardware. Trash it.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip


  #214   Report Post  
Old August 11th 03, 04:55 AM
Michael A. Terrell
 
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Keyboard In The Wilderness wrote:


Steel Mill Stories from the 40's (Maybe Urban Legend)


Armco (now A-K) Steel in Middletown Ohio supposedly had a man (who
was upset over his wife cheating on him) commit suicide by jumping into
one of the soaking pits were they heat the ingots before it is rolled
into sheet metal.

The country artist, Tom T. Hall, wrote and recorded a song called,
"The rolling mills of Middletown" about it. The company was going to
sue him over it, but they never did.

A friend of mine who worked there told me they had a big problem with
the old vending machines, and the company that owned them refused to
maintain them. Someone on night shift lost his last quarter in a Coke
machine so he got back on his fork lift, rammed the forks through the
machine, and dumped it into one of the empty soaking pits to watch it
melt.
--


Michael A. Terrell
Central Florida
  #215   Report Post  
Old August 11th 03, 04:55 AM
Michael A. Terrell
 
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Keyboard In The Wilderness wrote:


Steel Mill Stories from the 40's (Maybe Urban Legend)


Armco (now A-K) Steel in Middletown Ohio supposedly had a man (who
was upset over his wife cheating on him) commit suicide by jumping into
one of the soaking pits were they heat the ingots before it is rolled
into sheet metal.

The country artist, Tom T. Hall, wrote and recorded a song called,
"The rolling mills of Middletown" about it. The company was going to
sue him over it, but they never did.

A friend of mine who worked there told me they had a big problem with
the old vending machines, and the company that owned them refused to
maintain them. Someone on night shift lost his last quarter in a Coke
machine so he got back on his fork lift, rammed the forks through the
machine, and dumped it into one of the empty soaking pits to watch it
melt.
--


Michael A. Terrell
Central Florida


  #216   Report Post  
Old August 11th 03, 05:03 AM
Roy Lewallen
 
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I recall having read that AC is considerably more dangerous, for the
reason that Howard stated. Furthermore, 60 Hz is just about the worst
frequency. This was determined by executing dogs in less enlightened
times. I've also read that Edison created and promoted the electric
chair, which was run from AC, to dramatize the danger of AC over DC. He
had a big investment in DC distribution systems and equipment, while
Westinghouse was promoting AC power distribution.

Roy Lewallen, W7EL

Paul Burridge wrote:
On Sun, 10 Aug 2003 11:26:32 -0700, "Howard Henry Schlunder"
wrote:


DC is safer than AC because it doesn't cause
ventricular fibrillation, so death by these shocks occur from organ damage
and falling off ladders and things.



Funny. I was always told that DC= 'dangerous current' as it's *more*
likely to cause fatalities. Perhaps someone can settle the matter?
--

"I believe history will be kind to me, since I intend
to write it." - Winston Churchill


  #217   Report Post  
Old August 11th 03, 05:03 AM
Roy Lewallen
 
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I recall having read that AC is considerably more dangerous, for the
reason that Howard stated. Furthermore, 60 Hz is just about the worst
frequency. This was determined by executing dogs in less enlightened
times. I've also read that Edison created and promoted the electric
chair, which was run from AC, to dramatize the danger of AC over DC. He
had a big investment in DC distribution systems and equipment, while
Westinghouse was promoting AC power distribution.

Roy Lewallen, W7EL

Paul Burridge wrote:
On Sun, 10 Aug 2003 11:26:32 -0700, "Howard Henry Schlunder"
wrote:


DC is safer than AC because it doesn't cause
ventricular fibrillation, so death by these shocks occur from organ damage
and falling off ladders and things.



Funny. I was always told that DC= 'dangerous current' as it's *more*
likely to cause fatalities. Perhaps someone can settle the matter?
--

"I believe history will be kind to me, since I intend
to write it." - Winston Churchill


  #218   Report Post  
Old August 11th 03, 07:35 AM
Tom Del Rosso
 
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Sir Charles W. Shults III wrote:
Actually, they ARE supposed to be conductive- at least to the
tune of about a megohm. In any operation that is serious about
antistatic procedures, the mats, wrist straps, and other equipment
are to be tested periodically. Most testers show if a mat reads open
right away. If you have mats or other equipment that read open,
then you have found defective hardware. Trash it.


A mega-ohm per what unit of distance? From any point on the mat to the
ground point?


  #219   Report Post  
Old August 11th 03, 07:35 AM
Tom Del Rosso
 
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Sir Charles W. Shults III wrote:
Actually, they ARE supposed to be conductive- at least to the
tune of about a megohm. In any operation that is serious about
antistatic procedures, the mats, wrist straps, and other equipment
are to be tested periodically. Most testers show if a mat reads open
right away. If you have mats or other equipment that read open,
then you have found defective hardware. Trash it.


A mega-ohm per what unit of distance? From any point on the mat to the
ground point?


  #220   Report Post  
Old August 11th 03, 07:54 AM
Sir Charles W. Shults III
 
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Actually, I should have said a megohm for a ground strap and 10 megohms or
so per square for mats. Since they are by area and not linear, the
specification has to be per square.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip


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