Upon taking your advice, and that of my scientific-son-in-law, who gave the
Sperry meter, I read the directions.

"Input impedance in DC and AC voltage ">10M (Omega)," so the meter meets your
criteria.

Thanks for the EE course.

"Yestieda, I couldn't spel inginir, now I are won."

Thanks,

Tom Hanlon
Palm Springs, CA
84 Westfalia

"Joe L." wrote:

> "electronic overload protection" sounds to me like the METER is protected
> from overload; if everything else melts down the meter will still be ok.
>      This is not to say "dont use it" but before you do further checking is
> needed. Somewhere in the instructions or on the meter itself there should be
> the number for "Input Impeadence". If this number is 10 meg ohms (sometimes
> written as 10,000K Ohms) or higher you should be fine (the symbol for ohms
> looks sort of like an upside-down "U").
>      If you cannot find this information anywhere on the meter or in the
> instructions call the maker. If you cannot find out then you have a decision
> to make. Either get another meter you KNOW is safe or take the chance of
> popping something VERY expensive with the meter you have.
>      I plugged your meter into a couple of search engines to see what came
> up. Nothing on your specific meter but I did find this:
>
> A.W. Sperry Instruments, Inc., 245 Marcus Blvd., Hauppauge, NY 11788;
> 516-231-7050.
>
>     They should have a tech support department that can tell you what you
> need to know.
>
> ----- Original Message -----
> From: Thomas D. Hanlon <hanran.inc@prodigy.net>
> To: Joe L. <jliasse@TOAST.NET>
> Cc: <vanagon@GERRY.VANAGON.COM>
> Sent: Friday, August 20, 1999 2:59 PM
> Subject: Re: Which Voltmeter to use?
>
> > Joe,
> >
> > Does a meter such as I have, the A.W. Sperry Model Dm-2a, described on the
> > packaging as having "electronic overload protection, meet your criteria?
> That
> > is, does that term mean, to you, " approved for use on computer
> > controlled-cars?"
> >
> > Features:
> >
> > UL Listed in US and Canadian Safety Standards
> > limited one-year warranty
> > ELECTRONIC OVERLOAD PROTECTION
> > autorangin
> > simple operation
> > continuity buzzer
> > rangehold button
> > built-in test leads...
> >
> > Cost appx $30.00...Usual disclaimers apply
> >
> > Tom Hanlon
> > Palm Springs, CA
> > 84 Westfalia
> >
> > "Joe L." wrote:
> >
> > >      Im no expert but one thing I DO know. If you are gonna mess around
> with
> > > any vehicle with a computer on it you MUST have a voltmeter with what is
> > > known as a "High Input Impeadence" (10 megs or higher). This is
> basically
> > > how much of a load the meter itself puts on a circuit when you use it.
> > >      What you do when you use a voltmeter is sort of the same thing you
> do
> > > when you plug the toaster into the wall socket; you add the meter to
> > > whatever curcuit you are testing and this increases the load on that
> > > circuit. Plug in one too many toasters and you blow the fuse. "Plug in"
> a
> > > low impeadence voltmeter and you blow the computer! This is why you will
> see
> > > words like "Approved for use on Computer Controlled cars"  on SOME
> > > voltmeters but not on others.
> > >      Nowadays it is pretty easy and inexpensive to find a suitable one
> > > (usually digital) but you cant just get whatever is cheapest at the
> Radio
> > > Shack.Sunpro puts out a deceint one ($40??) you can pick up at your
> local
> > > FLAPS.
> > >
> > > ----- Original Message -----
> > > From: Jeff Gilbert <jeff_gilbert@PEOPLESOFT.COM>
> > > To: <vanagon@GERRY.VANAGON.COM>
> > > Sent: Thursday, August 19, 1999 12:26 PM
> > > Subject: Which Voltmeter to use?
> > >
> > > > Hi,
> > > >
> > > > Im new to all this diagnosis stuff and was wondering if someone could
> shed
> > > > some light on what would be a good voltmeter to aid in the diagnosis
> of a
> > > > never ending, son of a bitch, fuel injection problem.  Bently suggests
> > > > using the VW meter...is this necessary, or will any good quality meter
> do?
> > > >
> > > > Thanks,
> > > >
> > > > Jeff
> >
> >
> >