Date:         Thu, 26 Aug 1999 17:17:42 -0500
Reply-To:     Darrell Boehler <midwesty@MIDWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Darrell Boehler <midwesty@MIDWEST.NET>
Subject:      Re: Which Voltmeter to use?
Content-Type: text/plain; charset="iso-8859-1"

Hi Coby,
    What an excellent idea.  I have used the same old fluke lcd meter for 20
years. This meter was so advanced when I acquired it I thought it would be
my last meter. Of course I felt the same way about the simpson 260 meter I
bought 20 years before that. Maybe one with a min - max will be my last one,
thanks for the tip.
Darrell

----- Original Message -----
From: Coby Smolens <cobys@WELL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, August 26, 1999 4:31 PM
Subject: Re: Which Voltmeter to use?


> I like David's list, I would add only one thing to the "should-have"
> section: Min-max record. This is invaluable (read that extremely valuable)
> in finding "drop outs", as in when a bad temp T2 sensor in an aircooled
van
> reads just fine in the shop, but suddenly kills the engine on the freeway.
> With min-max on you can record the battery voltage spike that occurs when
> the resistance between the sensor and ground goes to infinite. Or you can
> record the voltage return to the ECU from the airflow meter and pick up
the
> voltage drop when the circuitry in the meter breaks down momentarily.
These
> things tend to happen too fast and too sporadically to be tested for in
> bench test conditions.
>
> Coby Smolens, Owner
> Valley Wagonworks
> "Intimately acquainted with VW Vans since 1959"
> 1535 Sir Francis Drake Blvd.
> San Anselmo, CA 94960
> Phone: (415) 457-5628
> Fax: (415) 457-0967
> http//:wagonworks.com
> mailto:contact@wagonworks.com
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
> Of David Beierl
> Sent: Thursday, August 19, 1999 11:30 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Which Voltmeter to use?
>
>
> At 16:26 8/19/99 +0000, Jeff Gilbert wrote:
> >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?
>
>
> I would suggest a meter with at least ten megohm input resistance on DC --
> most digital meters will meet this, while cheap analog meters may have
only
> a few thousand ohms resistance on low volt scales.  Accuracy of +/- one
per
> cent is plenty.  Desiderata include:
>
> Removable test leads with banana plugs -- there is a wide assortment of
> leads available with clips, interchangeable tips etc.
>
> Separate connections for volts and amps -- this is a nuisance but sooner
or
> later will save you blowing a meter fuse or worse.
>
> Ten amp range -- actually you can build a shunt to measure any conceivable
> current but it's a pain.
>
> Bar-graph meter display which reacts faster than the numerical display.
>
> If auto-range, switchable to manual
>
> Diode-check voltage of three volts -- this isn't common, but it will let
> you check most LEDs.  Usually it's 1.5, which is fine for regular
> diodes.  Not a biggie...
>
> Continuity beeper -- these vary widely as to what the consider
"continuity"
> so read the manual.  Some are as high as 1500 ohms, which isn't very
useful
> in an automotive setting.
>
> Low DC volt scale that lets you measure ten millivolts or less -- most
> digital meters have this.
>
> Peak Hold -- holds peak reading until you release it.  Handy, but not
> common.
>
> Differential Reading -- once you designate a reading, meter displays
> difference btw that and the current reading.  Handy, but not common.
>
> Ohms scale ten megohms or more.  This is common, but the cheapies
sometimes
> only go to 1 megohm; acceptable but not desirable.
>
> Things that don't matter:
>
> True RMS reading -- this is only for AC.  It's a good thing, but no help
> with the van.
> Capacitor testing -- good for electronics, but seldom useful with the
> van.  It will show the value of a cap, but won't show whether it breaks
> down at operating voltage.
> Transistor testing -- only electronics
> Super accuracy -- nice to have, but it costs out of proportion.
>
> david
>
>
> David Beierl - Providence, RI
> '84 Westy "Dutiful Passage"
> '85 GL "Poor Relation"
>