Is diesel fuel a conductor?

kubeek

Joined Sep 20, 2005
5,732
I have no idea if it is, but you definitely should not rely on it in either case, unless you want to end up engulfed in flames.
I think that this question is stupid enough for the thread to be locked.
 

jpanhalt

Joined Jan 18, 2008
10,110
Diesel fuel is a hydrocarbon. It is a non-conductor. That probe depends on the fact that water is heavier than diesel, so the diesel floats. The probe measures conduction in the lower layer, which is water.

As for flammability, diesel flash point is above 300°F or so. While it is an excellent fuel, I have read that it is not regulated as a flammable liquid in the US, because its flash point is so high. There is a huge difference between gasoline and diesel in terms of danger from combustion of fumes.

John
 

SgtWookie

Joined Jul 17, 2007
22,210
I don't think the question is stupid nor particularly hazardous.

Refined hydrocarbon/petroleum products are generally poor conductors. This can be a problem due to build-up of static electricity, eventually causing an arc. Sometimes, additives are used to increase the conductive properties to reduce/eliminate the static problem.

I don't know who might and who might not add such additives.

Some reading material:
http://www.biodiesel.org/pdf_files/fuelfactsheets/electrical_conductivity.pdf
http://books.google.com/books?id=3FkMrP4Hlw0C&pg=PA14&lpg=PA14&dq=Petroleum+products+conductivity&source=bl&ots=s0yVfMBGqY&sig=mQcKCaIkViHLWXWz2p-k6XIn01Q&hl=en&ei=R1KTTZGkGOTE0QGCn93MBw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBcQ6AEwADgK#v=onepage&q=Petroleum products conductivity&f=false
http://www.astm.org/Standards/D4308.htm
http://www.fiberglasstankandpipe.com/handlingpetrol.htm
http://www.smb-group.de/mla-900-conductivity-en.html
 

THE_RB

Joined Feb 11, 2008
5,438
Most car fuel tanks on older vehicles (both diesel and gasoline) use fuel sensors that are a wire wound pot with a metal wiper, and most parts of the live wiring (0v to 12v DC) are in direct contact with the fuel.

I think it is fairly unfashionable on newer cars though. Personally I would try to keep electricity well insulated from any liquid that burns. :eek:
 

mbohuntr

Joined Apr 6, 2009
432
Most car fuel tanks on older vehicles (both diesel and gasoline) use fuel sensors that are a wire wound pot with a metal wiper, and most parts of the live wiring (0v to 12v DC) are in direct contact with the fuel.

I think it is fairly unfashionable on newer cars though. Personally I would try to keep electricity well insulated from any liquid that burns. :eek:
That would explain why the needle would bounce all over the place!!
Thanks for that! ..... I had forgot about watching it move on rough roads...:D
 

BillB3857

Joined Feb 28, 2009
2,534
What about the "in the tank" fuel pumps. The fuel level is used as a cooling agent for the pump motors, which are usually brush type motors.
 

bribri

Joined Feb 20, 2011
143
well, i was told in school, that to drop a lit match in a pan of diesel is to watch it drown and go out.
diesel ignites under pressure.
gasoline however is more prone to creating fumes which will deflagrate (explode) at the slightest spark.
i'm just saying what i've heard in terms of combustion.
in my little world i have no reason to believe that diesel fuel is an isolator.
 

Wendy

Joined Mar 24, 2008
22,156
There are plenty of other kinds of sensors. I lean toward optical sensors, but they have their own problems (mostly with getting dirty). I remember hearing about TACAMO (ELF Radio for subs) had a problem with interferance, so they used optical fibers to detect the aircrafts fuel level.
 

Oclaf

Joined Mar 26, 2011
15
Probably no use to you but while I was working industrial maintenance I did a repair on an oil level sensor in an old (1940's) blower.
It was very basic consisting only of a tube containing a reed switch and a magnetic float around the tube that activated the reed switch when the oil level fell. Good simple solution to level sensing.

As for your question diesel is a decent insulator. Oil is often used as an insulator. Large transformers have oil flowing within the windings as coolant.
 

bribri

Joined Feb 20, 2011
143
As for your question diesel is a decent insulator. Oil is often used as an insulator. Large transformers have oil flowing within the windings as coolant.
interestingly (i just looked this up), bio-diesel is a better conductor than petro-diesel.
higher conductivity in a fuel is actually safer because of its ability to dissipate static electricity. low conductivity fuels can accumulate electrical charges which may dissipate in the form of a spark (fire hazard). as it turns out, low conductivity fuels have been blamed for petroleum depot fires in the past.
for this reason, chemicals are added (at refineries) to diesel in order to make it more conductive.
 

Thread Starter

victorment

Joined Jul 4, 2010
52
is there a sensor that detects diesel and output some voltage value and detect an unleaded fuel that also outputs another voltage value?
 

HallMark

Joined Apr 3, 2011
89
If you are making anything related to fuel level sensing then you must have to take care of the components you are using this project.
 
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