G-Tech meter

[Jeffrey Engel]

> Date:          Thu, 1 May 1997 10:00:54 -0500 (CDT)
> To:            diy_efi at coulomb.eng.ohio-state.edu
> From:          cloud at peaches.ph.utexas.edu (Tom Cloud)
> Subject:       Re: G-Tech meter
> Reply-to:      diy_efi at coulomb.eng.ohio-state.edu

> >I bought a G-Tech meter and it pretty much works.  You have to be on a
> >flat, level road for the thing to work correctly, though.  Since it uses
> >an accelerometer for all of its calculations, it can get thrown off
> >pretty quickly.  For example, if you are going up a hill, the
> >accelerometer will think you are going faster than you really are.  You
> >could even park your car on a hill, and G-Tech will think you are
> >accelerating continuously.  The device is also only accurate for HP,
> 
> I'm confused .... an accelerometer is an "AC-coupled" device.
> I.e. it only detects a "change" in velocity.  If it reads while
> sitting still or when the speed is constant, it must be a weight
> hung on a pot, not a 'real' accelerometer.
> 
> Tom Cloud <cloud at peaches.ph.utexas.edu>
> 

The weight-on-a-pot setup has too much friction to give repeatable 
results.  More modern units are weight-on-a-strain-gage.  I'm not 
sure at all what the current state-of-the-art is.

je
jengel at fastlane.net

     "I can resist anything but temptation"
                                  Mark Twain