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'[OT] Emissions from Cell phones and Gasoline pumps'
1999\10\08@093121 by Andy Kunz

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I just received this as part of my morning news.

Question for those in the know:  Are these things really putting out enough
of a voltage to arc and cause a fire?  Or is this because the cell phones
clobber the micro metering the fuel?

Andy

*** BP Amoco curbs cellular phone use

CLEVELAND (AP) - BP Amoco is warning customers not to use cellular
phones near gasoline pumps, out of concern that electronic impulses
could start a fire. Although the risk is slight, the company doesn't
want to take any chances, BP Amoco spokeswoman Linda McCray said
Thursday. Other oil companies have plans for similar warnings, and
London-based BP Amoco has already put warning signs on gas pumps in
the United Kingdom and Australia. The signs will be placed at BP and
Amoco stations in the U.S. by the end of the year. "This is not a ban
- this is a precautionary warning," McCray said. She said the warning
does not apply to customers who are in their cars or in convenience
stores. See
http://www.infobeat.com/stories/cgi/story.cgi?id=2561534765-ab8


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1999\10\08@105055 by Reginald Neale

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>Question for those in the know:  Are these things really putting out enough
>of a voltage to arc and cause a fire?  Or is this because the cell phones
>clobber the micro metering the fuel?
>
>Andy
>
>*** BP Amoco curbs cellular phone use
>
>CLEVELAND (AP) - BP Amoco is warning customers not to use cellular
>phones near gasoline pumps, out of concern that electronic impulses
>could start a fire. Although the risk is slight, the company doesn't
>want to take any chances, BP Amoco spokeswoman Linda McCray said

Well, I'm not "in the know." But that never stopped me before.... ;-) so my
guess would be the latter. Wouldn't it be the cell phone mfr who was
issuing the warning if the former?

A couple of years ago at a seminar, I think it was Analog Devices, the
presenter was talking about the importance of board layout in reducing
pickup from EMI. He told the story of the digital gas pump display mfr who
hadn't done a good enough job. A trucker noticed that when he keyed his CB
while pumping fuel, the display reset to all zeroes. In a matter hours,
truckers all over the nation were alerted to look for this brand of pump.
The mfr lost a bundle before they could even start damage control.

BP Amoco could be worried about customer safety. Or they could know
something we don't.

Reg Neale

1999\10\08@105303 by wwl

picon face
On Fri, 8 Oct 1999 09:29:30 -0400, you wrote:

>I just received this as part of my morning news.
>
>Question for those in the know:  Are these things really putting out enough
>of a voltage to arc and cause a fire?  Or is this because the cell phones
>clobber the micro metering the fuel?
>
>Andy
>
Could be either - I doubt the RF could cause ignition,  but as phones
are not intrinsically safe, the battery presents a possible ignition
source under fault conditions.

1999\10\08@105307 by Nicholas Irias

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I have seen safety warnings about this before.  The claim is that cell
phones draw relatively high currents, so if while you're talking the battery
contacts move and arc, there is a tiny spark that could ignite gasoline
vapor.  The arc of course is smaller than the arc at the brushes of your
car's starter motor, the spark caused by someone pulling into the station
and backfiring, the static electricity shock you sometimes get when you try
to get back into your car in dry weather , etc.  And of course there needs
to be so much gasoline vapor in the air that you are over the lower
expolosive limit.

There are no statistics on how often cell phones have causes fires, so we
can onlly guess how often it happens.  My guess is that it is an urban
legend style theory and that cell phones have NEVER been proven to have
caused a fire or explosion at a gas station.  I would expect that you are
more likely to be simultaneously hit by a meterorite and a lightning bolt
while pumping gas than to have your cell phone cause an explosion.

{Original Message removed}

1999\10\08@112636 by John Mitchell

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On Fri, 8 Oct 1999, Mike Harrison wrote:

>I just received this as part of my morning news.
>
>Question for those in the know:  Are these things really putting out enough
>of a voltage to arc and cause a fire?  Or is this because the cell phones
>clobber the micro metering the fuel?
>
>Andy

considering the number of retards I've seen smoking at the pump, my guess
is you're safe to use your cellphone.  Always better to be safe than sorry
though.


- j

1999\10\08@113914 by Wagner Lipnharski

picon face
Gasoline vapors creates a highly flammable/explosive area. Any device
that can create a spark, electric or not should be classified as
"intrinsic-safe" to operate near or inside such area. It means no
sparkling material, sealed batteries and contacts, and so on.

If you take a look, all the metals at the pump hose and housing is made
from Aluminum or Zamak, that does not generate sparks.  This is also the
main reason why the gasoline intake receptacle in the cars are always at
the other side of the vehicle's engine, or at least not to close.  All
the safety precautions about it include the fact that before you feed
any gasoline into your car you should press a button or touch the pump
in anyway to discharge any static voltage present at your own body.

This is why in some gas stations they recommend passengers to *stay*
into the vehicle while the driver take care of the gas pump.  But even
after all these recommendations and safe advices, here in Florida is
common to see people pumping gas and ... "smoking" at the same time, it
is incredible the very low incidence of accidents caused by it.

Just a word of advice:  If there is no wind at all during pumping gas,
just wait few more seconds before you turn on your car's engine start
key to leave the station...

1999\10\08@114718 by Alan Pearce

face picon face
>I have seen safety warnings about this before.  The claim is that cell
>phones draw relatively high currents, so if while you're talking the battery
>contacts move and arc, there is a tiny spark that could ignite gasoline
>vapor.  The arc of course is smaller than the arc at the brushes of your
>car's starter motor, the spark caused by someone pulling into the station
>and backfiring, the static electricity shock you sometimes get when you try
>to get back into your car in dry weather , etc.  And of course there needs
>to be so much gasoline vapor in the air that you are over the lower
>expolosive limit.

The problem is more likely to be the RF field strength causing arc in rusting
pop riveted joints in the pump casing. I would doubt that a cell phone could
generate a high enough field to do this, unless it was one of the original style
ones with the separate handset. This was a very definite problem with radio
telephones where the transmitter power was several watts.

A more likely problem is using any sort of transmitting device where explosives
are being used. The wires to the detonator make a very good aerial system at any
frequency and result in a current inside the detonator which is enough to heat
it sufficiently to explode. These days ferrite beads are put in to attempt to
stop this happening.

1999\10\08@121439 by John C. Frenzel

picon face
>
> Question for those in the know:  Are these things really putting out
enough
> of a voltage to arc and cause a fire?  Or is this because the cell phones
> clobber the micro metering the fuel?
>
> Andy
>
I would guess neither.  Another lawyer getting geared up to sue.  Anybody
read the WSJ article on the impact of cell phone emmisions on aircraft
avionics.   They could not find a single instance of interference, not even
in the lab.   They just want you to use the expensive airphone service that
they own instead.  Now I am not going to key my TS-130 at the gas pump (100W
output), but the cell phone is a non issue.
John


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Bid and sell for free at http://auctions.yahoo.com

1999\10\08@122252 by Nicholas Irias

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Sounds like Amaco should remove the detonators from their gas pumps.  They
can always install a detonator later when it is time to blow up an old pump.

>
>A more likely problem is using any sort of transmitting device where
explosives
>are being used. The wires to the detonator make a very good aerial system
at any
>frequency and result in a current inside the detonator which is enough to
heat
>it sufficiently to explode. These days ferrite beads are put in to attempt
to
>stop this happening.
>

1999\10\08@122630 by Craig Lee

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face
> These days ferrite beads are put in to attempt to stop this happening.

To attempt-to-stop-this-from-happening...  I don't know what I'm more
scared of --- unsafe, or sort-of-unsafe...

About 10 years ago, working at NovAtel, we had a phone that would actually
cause the car's ignition to misfire (I think it was a Honda).  Funny thing
since the transceiver was in the trunk and the ignition was under the hood.

About 7 years ago, also at NovAtel, we had a radio modem we OEM'd to IBM.
The modem was integrated into a laptop.  One day while demonstrating it in
a boardroom, the thing exploded, spraying chicklets(keycaps) all over the
room!  Yes indeed, the devastating combination of a lithium ion battery,
no short protection, and a poor quality flex strip.

As far as the gas pump internals, the electronic bits are typically
seperated from the fuel by a 1/2" iron shield, and in Canada they have to
pass CSA for intrinsic safety, and the Federal Weights and Measures has to
certify accuracy. Thus includes external ability to influence the
measurement
with perhaps RF, slow flow, fast flow, remote control, etc.

Craig

1999\10\08@124726 by Andy Kunz

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>read the WSJ article on the impact of cell phone emmisions on aircraft
>avionics.   They could not find a single instance of interference, not even

I mentioned this to a stewardess last flight, and she said "It can't be too
bad - the pilots use them all the time."

Andy

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1999\10\08@125545 by Joseph Rutsky

picon face
This was a topic on the news the other day.  I guess that the government went
with the rule as more of a "better safe than sorry" rule than one that had been
substantiated.

Joe Rutsky

1999\10\08@132254 by Sean H. Breheny

face picon face
I've always been told that the problem is with billing,not safety. If your
celphone is at 30,000 ft., which cell are you going to be talking to? The
answer is about 20 at one time!

Sean

At 12:43 PM 10/8/99 -0400, you wrote:
{Quote hidden}

| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
\--------------=----------------
Save lives, please look at http://www.all.org
Personal page: http://www.people.cornell.edu/pages/shb7
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1999\10\08@133318 by John De Villiers

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face
> >Question for those in the know:  Are these things really putting
> out enough
> >of a voltage to arc and cause a fire?  Or is this because the cell phones
> >clobber the micro metering the fuel?
> >
> hadn't done a good enough job. A trucker noticed that when he keyed his CB
> while pumping fuel, the display reset to all zeroes. In a matter hours,

So what does this mean for PIC's. Will a pic work near a cell phone, ie can
i use a pic to talk to my cell and send me automated sms messages, or will
the cellphone itself sort of throw that idea out the window?

Anyone ever tried this? I can send sms messages with my phone connected to
my pc, why cant i do it with a PIC also ???

John

1999\10\08@133522 by Michael Lee

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face
> I would guess neither.  Another lawyer getting geared up to sue.  Anybody
> read the WSJ article on the impact of cell phone emmisions on aircraft
> avionics.   They could not find a single instance of interference, not
even
> in the lab.   They just want you to use the expensive airphone service
that
> they own instead.
> John

This is certainly not my experience!  I work in the microwave/avionics
industry, and quite often have problems with mobile phones interfering with
my measurements in the lab.

The rules governing the use of mobile phones and other electronic equipment
within aircraft probably know a lot more about EMI the you.  Would you wish
to be responsible for an aircraft missing a nav beacon in bad visibility ?

My advice to all would be to follow the rules, they are for your safety !

Mick

1999\10\08@153634 by Anne Ogborn

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Speaking of RF emissions and stupid human tricks,

I was up at the observatory near here. The hilltop is
festooned with all sorts of instrumentation - antennas everywhere,
strange looking buildings, etc.
There are signs everywhere clearly reading "Radio Transmissions
Prohibited in this Area - Sensitive Scientific Equipment"
Yep - some knuckle dragging ham operator was there
yacking away.

Wonder how many thousands of dollars of experimental time he
ruined.

1999\10\08@161235 by Dave VanHorn

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face
> I was up at the observatory near here. The hilltop is
> festooned with all sorts of instrumentation - antennas everywhere,
> strange looking buildings, etc.
> There are signs everywhere clearly reading "Radio Transmissions
> Prohibited in this Area - Sensitive Scientific Equipment"
> Yep - some knuckle dragging ham operator was there
> yacking away.
>
> Wonder how many thousands of dollars of experimental time he
> ruined.


I hope you kicked his ass.. (Speaking as president of the local ham club)

"Failure is NOT an option! It's part of the operating system!"
Where's dave?  Try http://www.aprs.net:8000/kc6ete-9

1999\10\08@163744 by fernteix

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In the vicinity of the phone can be found induced voltages. If some
connection behaves as a LC resonant circuit and the working frequency  used
in the cell phone can appear significative  voltages in that circuit which
can generate a very small spark but sufficient for ignition,if the
percentage of oxygen is adequate .
At least is my opinion.

Fernando

{Original Message removed}

1999\10\08@164810 by Dave VanHorn

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> In the vicinity of the phone can be found induced voltages. If some
> connection behaves as a LC resonant circuit and the working frequency
used
> in the cell phone can appear significative  voltages in that circuit which
> can generate a very small spark but sufficient for ignition,if the
> percentage of oxygen is adequate .
> At least is my opinion.


You're aware of course that your car, rolling down the road, can generate a
large static charge, FAR larger than anything the phone could produce.
Maybe we should ban cars at gas stations too?

I rather doubt you could demonstrate a spark, even from a full power bag
phone under ideal conditions. Speaking here as a 10 year ham operator with a
car that looks like a porcupine, and no transmitter less than 30W onboard.

Will we ban police cars from gas stations too? They have radio systems that
are active continuously.

This kind of knee-jerk lawyerism is classic "junk science".

1999\10\08@165434 by paulb

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face
Dave VanHorn wrote, quoting Anniepoo:

>> Yep - some knuckle dragging ham operator was there
>> yacking away.
> I hope you kicked his ass.. (Speaking as president of the local ham
> club)

 Hmmm, that's why I eschew the term "ham".  I suspect she is using the
now-common application of the term to mean "CB operator", not us.
--
 Cheers,
       Paul B.

1999\10\08@170033 by Dave VanHorn

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>   Hmmm, that's why I eschew the term "ham".  I suspect she is using the
> now-common application of the term to mean "CB operator", not us.


Could have been some LID hiltopping, but with the area clearly posted, I
think he deserves some heat.

Could have been a CB yahoo too, not enough details.


We had one nut that used to fly his O-2 through the beam at the GTE ground
station in Hawaii.. It's a 105' dish, with 100kW going up the pipe. They
could see him in the beam when the signal strength on the RX side dropped
down.

And they say evolution is just a theory...

1999\10\08@170040 by Lee Jones

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face
>> Anybody read the WSJ article on the impact of cell phone
>> emmisions on aircraft avionics.   They could not find [any]

> This is certainly not my experience!  I work in the microwave/avionics
> industry, and quite often have problems with mobile phones interfering with
> my measurements in the lab.
>
> The rules governing the use of mobile phones and other electronic equipment
> within aircraft probably know a lot more about EMI the you.  Would you wish
> to be responsible for an aircraft missing a nav beacon in bad visibility ?

There is no FAA rule against using cellphones or other transmitters
(such as amatuer radio) in an aircraft.  It's left up to the operator
(i.e. aircraft owner and pilot in command).

> My advice to all would be to follow the rules, they are for your safety !

It's an FCC rule against cellphones being used in aircraft.

                                               Lee Jones

1999\10\08@170656 by Andy Kunz

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>Will we ban police cars from gas stations too? They have radio systems that
>are active continuously.

Ban them from operating radar in the vicinity of civilian passenger
vehicles.  You know what could happen if one of them ignited a car's
occupants <G>?  How about knocking out a pacemaker? :-(

This isn't where I was hoping the thread would go, but I sure have learned
a lot!

Thanks!

Andy

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1999\10\08@170847 by Thomas C. Sefranek

face picon face
Dave VanHorn wrote:

> > I was up at the observatory near here. The hilltop is
> > festooned with all sorts of instrumentation - antennas everywhere,
> > strange looking buildings, etc.
> > There are signs everywhere clearly reading "Radio Transmissions
> > Prohibited in this Area - Sensitive Scientific Equipment"
> > Yep - some knuckle dragging ham operator was there
> > yacking away.
> >
> > Wonder how many thousands of dollars of experimental time he
> > ruined.
>
> I hope you kicked his ass.. (Speaking as president of the local ham club)
>
> "Failure is NOT an option! It's part of the operating system!"
> Where's dave?  Try http://www.aprs.net:8000/kc6ete-9

One wonders if this is a TROLL?
Which Observatory, Millstone?  Haystack?
(But Ham radio is NOT immune to the demographics of the general public.)

--
Thomas C. Sefranek  WA1RHP
ARRL Instructor, Technical Specialist, VE Contact.
http://www.harvardrepeater.org
http://hamradio.cmcorp.com/inventory/Inventory.html

1999\10\08@171246 by Thomas C. Sefranek

face picon face
Dave VanHorn wrote:

> > In the vicinity of the phone can be found induced voltages. If some
> > connection behaves as a LC resonant circuit and the working frequency
> used
> > in the cell phone can appear significative  voltages in that circuit which
> > can generate a very small spark but sufficient for ignition,if the
> > percentage of oxygen is adequate .
> > At least is my opinion.
>
> You're aware of course that your car, rolling down the road, can generate a
> large static charge, FAR larger than anything the phone could produce.
> Maybe we should ban cars at gas stations too?
>
> I rather doubt you could demonstrate a spark, even from a full power bag
> phone under ideal conditions. Speaking here as a 10 year ham operator with a
> car that looks like a porcupine, and no transmitter less than 30W onboard.

Dave,

Are you saying you TRANSMIT while pumping?

(Having had the benifit of training from my rich uncle Samuel in flight school,
I can readilly agree with having the car body GROUNDED before fueling!

I can demonstrate a spark just getitng out of the car on some days.
I can immagine a good current path between the car body and the pump nozzel.

I remember fuel truck dragging chains (Sparking !!!) down the road.
(To prevent static!!!)

All of this add  up to;

If you want safe, you don't do some things.
If you want MONEY you pass laws.

> Will we ban police cars from gas stations too? They have radio systems that
> are active continuously.
>
> This kind of knee-jerk lawyerism is classic "junk science".

--
Thomas C. Sefranek  WA1RHP
ARRL Instructor, Technical Specialist, VE Contact.
http://www.harvardrepeater.org
http://hamradio.cmcorp.com/inventory/Inventory.html

1999\10\08@172341 by Dave VanHorn

flavicon
face
> Are you saying you TRANSMIT while pumping?

Me, and the cops too.

> (Having had the benifit of training from my rich uncle Samuel in flight
school,
>  I can readilly agree with having the car body GROUNDED before fueling!

That's what the hose nozzles are for.

1999\10\08@180528 by Agnes en Henk Tobbe

flavicon
face
IMHO this is turning things upside down and my advice to everybody is to
protest loudly against this sort of publications. Recently in an Australian
bank branch I saw a similar notice. There they were so honest to confess
that the emissions might interfere with the data processing equipment.....

Firstly: any 900 MC or even 1800 MC emission from a cellular phone with the
power used and antenna efficiency can only be harmful at distances of less
than 10 - 20 cm. (Yes, keep the antenna away from the grey matter or eyes
over prolongued periods).
Secondly: modern low signal levels in digital equipment can be  more easily
disturbed by RF radiation than older equipment (yes, the electronic meter
could go wild, probably when you hold the phone next to the board of the
counter). But that is - again IMHO - NOT the concern of the user of the RF
emissions but of the user of the sensitive equipment. This equipment should
be able to work in an environment where RF emissions are present, whatever
the source. Because RF emissions are everywhere and at a never predictable
level: the petrol station next to the local FM broadcasting antenna; next to
a ham radio operator; the passing police cruiser, the CB operator.....Not to
mention al the RF pollution and spikes on the mains supply that feeds the
poor PIC or other controller.
Proper RF shielding and design rules are also necessary as modern digital
equipment can emit RF radiation with a fieldstrength within the confines of
the equipment that could reach the same level as caused by a cellular phone
at a distance of say 2 meters... I have more problems with the RF emitted by
my PIC controlled roger beep/morse keyer that causes interference while
listening to other ham-operators on certain bands than the PIC has with my
400 watt RF emissions.
BTW , Micheal Lee: why do you not design your avionic electronics in such a
way that they are immune? A plane is full of transmitters on all sorts of
frequencies and with higher fieldstrenght  than any cellular phone can ever
hope to produce?
Especially Germany seems to be the country to find more about this subject
as recently rules were published (not on the internet AFAIK) about
acceptable RF emission levels in cars to drive safely. Also rules to define
the acceptable level of RF field strength in and near private dwellings. For
those interested, try to get hold of the publications in CQ-DL  - the German
amateur radio magazine over the past 18 months.

Henk VK2GWK / PA0ADC

-----Oorspronkelijk bericht-----
Van: Andy Kunz <spamBeGonesupportspamBeGonespamMONTANADESIGN.COM>
Aan: TakeThisOuTPICLISTEraseMEspamspam_OUTMITVMA.MIT.EDU <RemoveMEPICLISTspamTakeThisOuTMITVMA.MIT.EDU>
Datum: vrijdag 8 oktober 1999 23:29
Onderwerp: [OT] Emissions from Cell phones and Gasoline pumps


>Question for those in the know:  Are these things really putting out enough
>of a voltage to arc and cause a fire?  Or is this because the cell phones
>clobber the micro metering the fuel?
>

1999\10\08@181357 by Wagner Lipnharski

picon face
Some international flights doesn't allow batteries inside the passenger
area. You need to check it in as normal luggage. Ok, passenger cabin is
pressurized, much more O2 than at the load compartment. No electronic
equipment should be "on" in most of the national flights. Electronic
here means "anything that uses batteries" not only related to radio
frequency emission.  Ask the captain if you can keep turning on and off
a simple small flashlight during take-off or landing.  The reduction of
lights inside the passenger cabin during take-off or landing should be
much more related to avoid possibility of sparks in lamps sockets (also
in case of accidents) other than just save 500 Watts in energy from
those huge jet compressors power plants...

Yes, I don't understand why we don't use ionization fans in gas stations
to discharge static from cars, or even a ground wire, or cooling the
combustible at the pump... just because we don't have much accidents by
this reason?... why flight passengers use a belly seat belt (two points)
while the crew use 3 points? pilot uses 4 points, isn't? ...why a 10,000
gallons of gasoline bombshell can travel right in front of your car at
the highway? ...what happens if your car's front tire blows up driving
at 70 mph? is there a way to avoid your car to rock and roll in that
situation? yes, but it cost, and it doesn't happens so often. ...why is
"a ok" to store 5 gallons of high flammable gasoline (for yard machines)
inside each american garage at 130¡F (summer) in a plastic container?

The answer is; just because we are not perfect, and we play this game of
living at the edge, until something bad happens, then a group of experts
will join to understand and solve the problem, when everybody knew the
answers years before. The '86 Challenger defective O-ring was a deadly
example. The part in use was defective for long, people knew that it
could cause leaking and fire, but... we can call this gambling with
luck? Yes, I think that we are a very lucky biologic engine.

1999\10\08@181813 by Max Toole

picon face
In a message dated 10/8/99 1:48:45 PM Pacific Daylight Time,
dvanhornEraseMEspam.....CEDAR.NET writes:

<< You're aware of course that your car, rolling down the road, can generate a
large static charge, FAR larger than anything the phone could produce.
Maybe we should ban cars at gas stations too?

I rather doubt you could demonstrate a spark, even from a full power bag
phone under ideal conditions. Speaking here as a 10 year ham operator with a
car that looks like a porcupine, and no transmitter less than 30W onboard.

Will we ban police cars from gas stations too? They have radio systems that
are active continuously.

This kind of knee-jerk lawyerism is classic "junk science".
 >>
Hi Dave and the list,
Speaking as a ham of 40 years, I would never key my transmitter in my vehicle
while gassing my vehicle.  This is different from a cell phone.  Your
transmitter poses no harm unless you key it.  Have you seen the signs in
blasting areas where the ask not to key transmitters?

Just an old timer's 2 cents worth.

Max, W5SEI

1999\10\08@192146 by Eric Smith

flavicon
face
> I would guess neither.  Another lawyer getting geared up to sue.  Anybody
> read the WSJ article on the impact of cell phone emmisions on aircraft
> avionics.   They could not find a single instance of interference, not even
> in the lab.   They just want you to use the expensive airphone service that
> they own instead.

There are two main reasons why they don't want you to use a cell phone in an
aircraft:

1)  Possibility of interference.  This may be negligible (or even zero) with
   a properly working phone.  What about damaged phones?  It's much easier
   for them to simply require that all radio transmitters and receivers be
   turned off.

2)  It's not going to work worth crap anyhow.  Depending on where you are,
   you'll key too many cell cites or none at all.  Even if it worked to
   some extent, you're going to have to do handoffs way too often, and
   you're likely to lose them.

1999\10\08@193557 by Dave VanHorn

flavicon
face
> Speaking as a ham of 40 years, I would never key my transmitter in my
vehicle
> while gassing my vehicle.  This is different from a cell phone.  Your
> transmitter poses no harm unless you key it.  Have you seen the signs in
> blasting areas where the ask not to key transmitters?

I'll gladly kill my transmitter in blasting areas, but I see no hazard at
the gas pump from any of my radios, LEAST of all my cellphone.

Are they banning Cops, CBs, Taxis....?
Are they banning rubber tires for the VERY significant charge they build up?

When they ban things that actually DO cause a problem, then we can talk
about the "polar bear rattle" end of the spectrum.

1999\10\08@193832 by Dave VanHorn

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>Because RF emissions are everywhere and at a never predictable
> level: the petrol station next to the local FM broadcasting antenna; next
to
> a ham radio operator; the passing police cruiser, the CB operator

Good point, we have a large gas station here in town that is literally at
the foot of an AM/FM/TV tower.. I think my puny emissions are hardly
significant in the face of it's multiple 10-50kW outputs.

1999\10\08@194428 by Dave VanHorn

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> ? Yes, I think that we are a very lucky biologic engine.

Call it luck of you will, I don't think there are any polar bears
hereabouts.

1999\10\08@203622 by Anne Ogborn

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>  Hmmm, that's why I eschew the term "ham".  I suspect she is using the
>now-common application of the term to mean "CB operator", not us.


No. It was an amateur radio rig. Typical car that looks like a Russian
trawler
and KB5DIP license plate. He whipped out a handheld unit (2meter??)
then changed to a mic plugged into something under the dash that I took to
be a HF rig. And he used his call sign (no, I didn't write it down, and it's
not KB5DIP).

1999\10\08@204926 by Anne Ogborn

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>One wonders if this is a TROLL?
>Which Observatory, Millstone?  Haystack?
>(But Ham radio is NOT immune to the demographics of the general public.)


certainly wasn't intended as a troll, and certainly not as
a dispersion on all hams, including the ones who got me started in
electronics lo years ago and to whom I'm eternally grateful.

I simply couldn't remember the name of the darn observatory. I've looked it
up - It's Lick Observatory, on Mt. Hamilton.

1999\10\08@230248 by Mike Cornelius

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Sorry to fill the list with more OT banter...

As a point of interest these notices appeared in Australia not long after
the network operators introduced GSM mobile telephony. It is also worth
noting that the UK also uses GSM for mobile telephony.

I know nothing about fuel pumps but, as a GSM developer, I can confirm that
GSM is pretty harsh on nearby electronic devices. The problem is related to
the time division multiplexing and high instantaneous power of the GSM
transmission format.
A nearby GSM transceiver will introduce brief apparently randomly spaced but
repetitive bursts of 217hZ into pretty much any nearby AF system. Some
transceivers are worse than others but they pretty much all do it.

GSM doesn't tend to totaly devestate a micro based device like a very high
power nearby RF source might but it does have a habit of making its way into
sevsitive interface and data acquisition circuits.

For this reason GSM handsets are also banned in hospitals while AMPS
handsets were not.

Could this be related to the fairly recent introduction of GSM to the US ?
Most of the world (including au and uk) run GSM at 900 MhZ some parts of
Asia in particular run GSM at 1800 MhZ and the US use 1900 MhZ. The effect
that I have described certainly occurs with 900 MhZ systems but I'm not sure
about 1800 or 1900 MhZ systems. Can anybody out there confirm whether this
is the case ?

My guess is that if the fuel companies havn't made a fuss until now the
warning is much more likely to be related to billing rather than safety.
We've been using AMPS mobile phones near fuel pumps for 15 years. I reckon
that those signs would go up pretty quickly if someone actually got hurt.

Regards,

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mike Cornelius                  Internet: EraseMEmikespambytethis.com.au
Byte This Interactive           Phone:    +61 2 9310-2157
PO Box 1342 Strawberry Hills    FAX:      +61 2 9319-3948
NSW 2012 Australia              URL:      http://www.bytethis.com.au
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1999\10\08@231822 by Adam Langford

picon face
The company I work for has a  paintline where mobile phones and other battery
operated equipment are not allowed in the paint application rooms, not because
of induced voltages causing arcs, but from tiny arc from the battery terminals
themselves.  Although another part of the plant mobile phones and handheld RF
transceivers are not allowed due to them affecting the controllers for some
blow-off valves on a turbine air compressor.


{Original Message removed}

1999\10\09@002708 by Dave VanHorn

flavicon
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> The company I work for has a  paintline where mobile phones and other
battery
> operated equipment are not allowed in the paint application rooms, not
because
> of induced voltages causing arcs, but from tiny arc from the battery
terminals
> themselves.  Although another part of the plant mobile phones and handheld
RF
> transceivers are not allowed due to them affecting the controllers for
some
> blow-off valves on a turbine air compressor.

Explosive atmospheres are a whole 'nother thing, as is an environment where
you have a demonstrated problem.

I think the real issue is billing, they're afraid the pump might give out
some free gas, because they cheaped out their shielding.

1999\10\09@025415 by Dave Bell

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Michael Lee <RemoveMEM.D.LEraseMEspamEraseMEBTINTERNET.COM> wrote:

>The rules governing the use of mobile phones and other electronic
>equipment within aircraft probably know a lot more about EMI the you.

>My advice to all would be to follow the rules, they are for your safety !

Mick, Mick, Mick...

First, the "rules" don't know squat about EMI! And, giving you credit for
a pretty obvious syntactical error, the *makers* of the rules, probably
know *less* than the rules. As has been pointed out:

1) There is no FAA regulation preventing use of transmitters on board.

2) As reported, the pilots use them "all the time".

3) The airphone is not there for your convenience - it's there because it
  is profitable!

Yes, I'm cynical. I'm also pretty realistic. Feel free to not use your
cell phone, walkman, or flashlight. I'll feel free to do what I feel is
right for me...

Dave

1999\10\09@060255 by Russell McMahon

picon face
>Yes, I'm cynical. I'm also pretty realistic. Feel free to not use your
>cell phone, walkman, or flashlight. I'll feel free to do what I feel is
>right for me...
>Dave


Dave,

Please feel very free to tell me when you plan to fly in the same aeroplane
as me so that I can feel free to do otherwise :-)

In my country at least (much more technically backward apparently than
yours) it IS illegal to turn on a cellphone in an airliner.
That said, nobody ever accused our rule-makers of knowing what they were
talking about (on cellphones or otherwise).


regards,


     Russell McMahon

PS:     For those who may wonder, despite being marked [OT], I consider that
this is an on topic technical discussion (relating to EMC, regulations,
interpretation etc)
If you disagree, by all means please tell me but OFFLIST.


_____________________________

>From another world - http://www.easttimor.com

What can one man* do?
Help the hungry at no cost to yourself!
at  http://www.thehungersite.com/

(* - or woman, child or internet enabled intelligent entity :-))


{Original Message removed}

1999\10\09@094309 by Morgan Olsson

picon face
Hej Reginald Neale. Tack fšr ditt meddelande 10:49 1999-10-08 -0400 enligt nedan:


>He told the story of the digital gas pump display mfr who
>hadn't done a good enough job. A trucker noticed that when he keyed his CB
>while pumping fuel, the display reset to all zeroes.

Wonder who many of us start using the telephones at gas pumps now ;)

I believe the greatest risk is if you drip some gas, then drop your telephone off your pocket in the spilled gas on the concrete.  There might be sparks in the battery connection then, and also the battery or thelephone could short-cirquit some way.  Lying in the gas it is easy to ignite it.

Just a thought...

/Morgan
Morgans Reglerteknik, HŠllekŒs, 277 35 KIVIK, SWEDEN
  tel +46(0)414-446620, fax -70331,   RemoveMEmrtspam_OUTspamKILLspaminame.com

1999\10\09@204200 by Kevin J. Maciunas

flavicon
picon face
As a volunteer fire brigade person, let me add my $0.02 to this
discussion - it isn't the RF transmission which gives rise to the ban,
but the use of what we call "non intrinsically safe" handsets.  [This
means they **CAN** in theoy generate a spark].  We use handheld VHF
radios which aren't intrinsically safe; when we deal with explosive
atmospheres we have to use the intrinsically safe sets - each brigade
has but one of these.  In OZ, all of this stuff comes under the same set
of regulations, and it includes **EVERYTHING** - meaning, I suspect,
that you can't drive your car to the fuel supplier :-), nor can your
kids use a torch (US=Flashlight), nor probably anything else.  The signs
the proprietors put up amount to legal protection "We told you not to do
it!".
Lawyers!
/Kevin

--
-----------
Kevin J. Maciunas           Net: RemoveMEkevinTakeThisOuTspamspamcs.adelaide.edu.au
Dept. of Computer Science   Ph : +61 8 8303 5845
University of Adelaide      Fax: +61 8 8303 4366
Adelaide 5005
SOUTH AUSTRALIA

1999\10\10@030306 by Clyde Smith-Stubbs

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On Fri, Oct 08, 1999 at 11:13:19AM -0500, John C. Frenzel wrote:
> read the WSJ article on the impact of cell phone emmisions on aircraft
> avionics.   They could not find a single instance of interference, not even
> in the lab.   They just want you to use the expensive airphone service that

The reason for cellphones being banned on aircraft isn't actually interference
with avionics, but the fact that one phone can blanket several cells at once
due to the altitude.

Regarding interference, analog cellphones are relatively innocuous, but digital
phones (GSM anyway, not sure about CDMA) can and do cause problems with a number
of things; loud buzzing noises in audio circuitry are the most common. I've also
seen them upset a credit-card terminal (anywhere in the same room - most probabl
y
coupling into the magnetic-card reader head).

Radio transmitters of any kind are supposed to be turned off near gas pumps here
in Oz, I believe the possibility of ignition of fuel is a theoretical possibilit
y,
but I've never heard of it actually happening. Better safe than sorry.

Cheers, Clyde

--
Clyde Smith-Stubbs               |            HI-TECH Software
Email: EraseMEclydespamspamspamBeGonehtsoft.com          |          Phone            Fax
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1999\10\10@030515 by Clyde Smith-Stubbs

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On Sat, Oct 09, 1999 at 01:01:53PM +1000, Mike Cornelius wrote:

> that I have described certainly occurs with 900 MhZ systems but I'm not sure
> about 1800 or 1900 MhZ systems. Can anybody out there confirm whether this

Yes, I can confirm it does with 1900 MHz too - I have a dual band GSM phone and
while in the US I heard the same audio interference as I do in Australia.


Clyde

--
Clyde Smith-Stubbs               |            HI-TECH Software
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1999\10\10@031550 by Clyde Smith-Stubbs

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On Fri, Oct 08, 1999 at 06:13:37PM -0400, Wagner Lipnharski wrote:
> area. You need to check it in as normal luggage. Ok, passenger cabin is
> pressurized, much more O2 than at the load compartment. No electronic

Wrong, the baggage compartment is pressurized just like the cabin.

Virtually the entire fuselage is a pressure vessel - it would be hard
and inefficient to have pressurized bulkheads inside it.

--
Clyde Smith-Stubbs               |            HI-TECH Software
Email: KILLspamclydespamBeGonespamhtsoft.com          |          Phone            Fax
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1999\10\10@032423 by Clyde Smith-Stubbs

flavicon
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On Fri, Oct 08, 1999 at 11:52:35PM -0700, Dave Bell wrote:
> Michael Lee <@spam@M.D.L@spam@spamspam_OUTBTINTERNET.COM> wrote:
>
> 1) There is no FAA regulation preventing use of transmitters on board.

True, but there is an FCC one about not using cellphones while airborne.

> 2) As reported, the pilots use them "all the time".

It's quite normal for crew and passengers to use phones while
on the ground. In Australia, flight plans are supposed to be closed (known here
as "cancelling SARTIME") by phone rather than radio.

> 3) The airphone is not there for your convenience - it's there because it
>    is profitable!

We agree on that one. The rates are exorbitant!

Incidentally, there are documented cases of other electronic equipment (computer
s,
electronic games) affecting navigation equipment. These are probably due to EMI
with harmonics on the nav radio frequency (usually in the 100 MHz vicinity). Thi
s
is not likely to happen with a cellphone.


--
Clyde Smith-Stubbs               |            HI-TECH Software
Email: spamBeGoneclydespamKILLspamhtsoft.com          |          Phone            Fax
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1999\10\10@103928 by Wagner Lipnharski

picon face
Clyde Smith-Stubbs wrote:
>
> On Fri, Oct 08, 1999 at 06:13:37PM -0400, Wagner Lipnharski wrote:
> > area. You need to check it in as normal luggage. Ok, passenger cabin is
> > pressurized, much more O2 than at the load compartment. No electronic
>
> Wrong, the baggage compartment is pressurized just like the cabin.
>
> Virtually the entire fuselage is a pressure vessel - it would be hard
> and inefficient to have pressurized bulkheads inside it.

Oh, you are right, I forgot about big jets.

1999\10\10@234625 by nick

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picon face
I bought an am/fm radio to listen to at work. I keep it in my pocket
(with headphones). Every now and then I would get this really loud
digital noise for a couple of seconds. I thought that the unit was a bit
faulty being a digital radio I thought the display/processor was acting
up. Then when I was having a guitar lesson I heard the same noise and
finally I realised that the mobile phone ( the fist digital that I ever
owned) in my pocket was the culprit.

Now relate that to safety, I can understand that if a pilot gets on the
phone and sees the radio navigation go funny, then it is not a big deal
as he/she knows that while on the phone the readings are suspect. But
when someone in the passenger compartment is doing it, I think it is a
worry.


Nick

1999\10\11@143357 by Craig Lee

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> I believe the greatest risk is if you drip some gas, then drop
> your telephone off your pocket in the spilled gas on the
> concrete.  There might be sparks in the battery connection then,
> and also the battery or thelephone could short-circuit some way.
> Lying in the gas it is easy to ignite it.

Actually, amazingly enough, one of my certifiable friends is so
confident in the safety of gasoline that he actually extinguished
his cigarette in it!  I've seen it done, and in disbelief, no
explosion, and no flame.  So if the heat of the cigarette is not
hot enough to ignite gasoline, would the spark from a dropped cell
phone?

Getting back on topic,  is there an application note or some compiled
data on the PIC's RF immunity.

Our PCB designer designed a board where we integrated a 16C73A with
some Linx RF modules.  The transmitter module was placed directly
beside the PIC with the trace to the antenna looping through the PIC
pins and underneath it.  This was causing some definite problems, and
would only work properly when we re-routed the antenna trace.

So from my findings, with a 900 Mhz - 0 dBm transmission, RF does
effect the PIC.

Craig

1999\10\11@145256 by Dave VanHorn

flavicon
face
> Actually, amazingly enough, one of my certifiable friends is so
> confident in the safety of gasoline that he actually extinguished
> his cigarette in it!  I've seen it done, and in disbelief, no
> explosion, and no flame.  So if the heat of the cigarette is not
> hot enough to ignite gasoline, would the spark from a dropped cell
> phone?

Assuming there was a spark, yes. The burning cigarette is not as hot as you
think, and the energy expended in evaporating the gasoline cooled it off.

A steel spark is literally burning steel, which is quite hot.  I used
electrically generated sparks to ignite my butane torch yesterday to grill
some steaks.

I promise the gas pump gods that I will not stand in my gas tank, rapidly
connecting and disconnecting my battery, but I want to know what they are
going to do about the thousands of volts my car accumulates during the
average run.. In fact, since I have to make a run this afternoon, I'm going
to take my ESD meter, and measure the charge built up on my calibrated
standard ford explorer, on this standard fall afternoon in indiana.  Can
someone figure the approximate capacitance to ground of an explorer on 15
inch wheels?

> Our PCB designer designed a board where we integrated a 16C73A with
> some Linx RF modules.  The transmitter module was placed directly
> beside the PIC with the trace to the antenna looping through the PIC
> pins and underneath it.  This was causing some definite problems, and
> would only work properly when we re-routed the antenna trace.

One would sort of expect that. I bet the transmitter didn't live up to your
expectations either!

1999\10\11@180534 by Wagner Lipnharski

picon face
> Actually, amazingly enough, one of my certifiable friends is so
> confident in the safety of gasoline that he actually extinguished
> his cigarette in it!  I've seen it done, and in disbelief, no
> explosion, and no flame.  So if the heat of the cigarette is not
> hot enough to ignite gasoline, would the spark from a dropped cell
> phone?

I called my brother in law, he is an gas tank engineer at a quite large
gas company, talked about this subject for long time. I hope this can
clarify something.

The main point of the conversation was that gasoline DOES NOT BURN, what
burns is its vapor or its spray, because it needs oxygen *in the right
mix*, if not, it puts the fire away. So, a cigarette can be extinguished
in "liquid" gasoline if not producing sparks or ignite its 10cm vapors
above the liquid.

He also said that gasoline vapors are heavier than air, so it
concentrate close to the ground and even at the water drains close to
the gas pumps... dropping a cell phone close to it, even the
microscopics battery sparks ignite it with a nice explosion.  Of course
he confirmed that lots of places around gas tanks and pipes, it is
*forbided* to use any kind of "not intrinsical safe" electric/tronic
devices, and even key-rings are not allowed in some places.

Asked about car static electricity, he said that (because it is heavier
than air) gas vapors can not accumulate that high (close to the car
door's handlers) in open spaces as gas stations, normaly it fades away
horizontally all around, not that high.  His point is based on the
acidentally dropping of a cell phone at the floor as being the main
reason of the issue.

Ending the phone call, I asked him what happens if I generate a 10,000
volts electric red spark between two electrodes 3mm apart, half meter
deep inside liquid gasoline... he aswered: Absolute NOTHING, but don't
even think to do it. He said it is much more dangerous to be shaking
(playing with) your car's keys around gas vapors.

1999\10\11@182205 by Dennis Plunkett

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At 12:30 11/10/99 -0600, you wrote:
{Quote hidden}

No your friend is not certifiable, infact he may have an IQ greater than 80
<G>.
Your friend is quite correct. Petroleum as a liquid is not explosive (HAs a
surface temoperature of around -40oC, so putting it into the freazer will
make it get hotter <G>, only the vapors are dangerous.



Dennis

1999\10\11@224459 by Dave VanHorn

flavicon
face
> Ending the phone call, I asked him what happens if I generate a 10,000
> volts electric red spark between two electrodes 3mm apart, half meter
> deep inside liquid gasoline... he aswered: Absolute NOTHING, but don't
> even think to do it. He said it is much more dangerous to be shaking
> (playing with) your car's keys around gas vapors.

Indeed.. No air, no oxygen, no problem.


BTW: My "calibration run" was interesting. Highest potential measured was
3300V, lowest was unmeasurable. As expected, flinging off the highway at 65
directly into a gas station produced the highest reading, and motoring
around the city was teh lowest. I measured this by staying in the car, and
measuring the relative charge between myself/the car/ and the meter to the
pump.

In dryer weather, these readings will be much higher. The 3300V didn't give
me a noticable shock, but I have been shocked quite nicely in the winter.

One would suspect that when the nozzle approaches the tank, there might be a
spark.. Certainly much more likely than anything my cellphone is going to
do.

I also noticed another possible reason for not wanting cellphones at the
pump, COMMERCIALS!  A BP station here has sort of a radio station thing
going on their PA system at the pumps, but of course it's all commercials...

1999\10\12@032032 by Russell McMahon

picon face
>Actually, amazingly enough, one of my certifiable friends is so
>confident in the safety of gasoline that he actually extinguished
>his cigarette in it!  I've seen it done, and in disbelief, no
>explosion, and no flame.  So if the heat of the cigarette is not
>hot enough to ignite gasoline, would the spark from a dropped cell
>phone?

I feel certain that you could ignite petrol fumes with cellphone sparks
under some conditions.
BECAUSE-

Petrol liquid is NOT flammable.
ie Petrol is not a "mono-propellant"
If you can keep the air out you will not ignite petrol (liquid or vapour),
even  with an oxy-acetylene flame.

Petrol vapour  mixed with air (ideally 14:1 ratio) is highly flammable, as
we all know.

Properly mixed with air you MAY ignite the vapour with the smallest of
sparks.
YMMV

Long ago, we used to weld motorcycle petrol-tanks, on the bike, while
partially filled with petrol by RIGOROUSLY excluding air from the tank while
welding - I won't tell you our "safe" method less you do it wrong  and die.

BUT People die regularly while attempting to weld petrol tanks which have
been "scrupulously" cleaned and dried first. An airforce fitter died here
from a petrol explosion while gas-axing open a petrol drum which had sat
"empty" and uncapped for MONTHS on a  storage heap.


regards,



     Russell McMahon
_____________________________

>From another world - http://www.easttimor.com

What can one man* do?
Help the hungry at no cost to yourself!
at  http://www.thehungersite.com/

(* - or woman, child or internet enabled intelligent entity :-))


{Original Message removed}

1999\10\12@065806 by fernteix

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face
-----Original Message-----
From: Russell McMahon <TakeThisOuTapptech.....spamTakeThisOuTCLEAR.NET.NZ>
To: TakeThisOuTPICLISTKILLspamspamspamMITVMA.MIT.EDU <.....PICLISTspamRemoveMEMITVMA.MIT.EDU>
Date: Terga-feira, 12 de Outubro de 1999 8:20
Subject: Re: [OT] Emissions from Cell phones and Gasoline pumps [TECH non
electronic]


{Quote hidden}

That4s the importantest part of the question, in my opinion.

And how to get "the smallest sparks"? We can have very small sparks even
with very low voltages. To have a spark is necessary to have an electric
field higher  that a determined value that depends on the material:
dielectric rigidity .
So, to have a very small spark in a gas with a small induced voltage is only
necessary to have a very small gap between two electrodes with a difference
of potencial.

In VHF and UHF all practical connections have parasitic ressonant circuits
(as could be found in any UHF tuner design manual).This could amplify
voltage (not power...) according to transmission line theory. Even a hole in
a piece of metal is also equivalent to LC circuit, can have an high Q  and
have an associated ressonant frequency (as could be found to adjust the
coupling between UHF amplifier stages).  One of the  first radio receptions
was based on a LC ressonant circuit and a Branly (?) detector :  microsparks
between small pieces of metal in a glass tube result from small induced
voltages in antena amplified by the ressonant circuit.

So in my opinion  IF a microspark could be the beginning of the process, to
have an explosion is only a question of a misture with not too much or too
less oxygen.
My 1 cent...
Regards

Fernando

>Long ago, we used to weld motorcycle petrol-tanks, on the bike, while
>partially filled with petrol by RIGOROUSLY excluding air from the tank
while
{Quote hidden}

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