Exhaust Pressure sensing

les lesd at earthlink.net
Tue Mar 5 08:54:58 GMT 2002


No , it won't :)

Please read the Gas-Gay-Lussac law, it says:
" Gives the relationship between pressure and temperature when volume
and amount are held constant.
"

Well, when you have a copper pipe to drop the temp., the volume 
is NOT tied to pressure, simply because it's not a sealed container.
The amount of gas molecules in the pipe is more when the gas contracts
due to the lower temp. in the tube. More hot gas enters the tube to 
equalize the pressure. Why? Well, because if the tube has a lower
pressure
the gas outside at higher pressure finds the low pressure zone and fills
it until there is equilibrium.

-Les




> -----Original Message-----
> From: owner-diy_efi at diy-efi.org 
> [mailto:owner-diy_efi at diy-efi.org] On Behalf Of Eck, Joel
> Sent: Wednesday, February 27, 2002 7:14 AM
> To: diy_efi at diy-efi.org
> Subject: RE: Exhaust Pressure sensing
> 
> 
> Actually, it will. Check out this site: 
> 
> http://dbhs.wvusd.k12.ca.us/GasLaw/Gas-Gay-Lussac.html
> 
> It describes Gay-Lussac's gas law, which shows the direct 
> correlation between temperature and pressure of a gas given 
> contant amount and volume. As temperature increases, pressure 
> increases, and, as temperature decreases, so does pressure.
> 
> -----Original Message-----
> From: Greg Hermann [mailto:bearbvd at mindspring.com]
> Sent: Thursday, February 21, 2002 9:20 PM
> To: diy_efi at diy-efi.org
> Subject: Re: Exhaust Pressure sensing
> 
> 
> At 7:39 AM 2/21/02, Andris Skulte wrote:
> >Craig,
> > That sounds like an FSAE engine to me ;) If you have a length of
> copper
> >tubing, the temperature will have dropped plenty by the time 
> it gets to 
> >the gauge. How much the temp drop affects pressure, I'm sure 
> you could 
> >calculate based on some quick infrared gun measurements...
> 
> The temp drop will have NO effect whatsoever on the pressure 
> measurement.
> 
> Greg
> 
> 
> ----- End of forwarded message from owner-diy_efi at diy-efi.org -----
> --------------------------------------------------------------
> ----------
> ----
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
> quotes)
> in the body of a message (not the subject) to 
> majordomo at lists.diy-efi.org
> 
> ----- End of forwarded message from owner-diy_efi at diy-efi.org -----
> --------------------------------------------------------------
> --------------
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" 
> (without the quotes) in the body of a message (not the 
> subject) to majordomo at lists.diy-efi.org
> 
> 

----- End of forwarded message from owner-diy_efi at diy-efi.org -----
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org



More information about the Diy_efi mailing list