T&T: Multimeter, General Purpose for Boat, Advice Please

[Peter Bennett]

Saturday, February 17, 2007, 12:01:18 PM, Stephen wrote:

SO> I want to get a multimeter for general purpose use on the boat as we move
SO> aboard (beginning on the 24th).  What do List Members recommend for having
SO> around for circuit testing, current leaks, connectivity, and etc.'s that I
SO> haven't even thought of?  I should be good for batteries with the Heart
SO> Interface to the Freedom 20 for battery circuits; or is that a bad
SO> assumption?
 
SO> Having asked that question, I should add that maybe it is not one electrical
SO> test instrument but multiple boxes that I should consider adding to the
SO> live-aboard stores.  If this is so, I would appreciate help in narrowing
SO> down the number and size of boxes, due to on-board storage limitations.
SO> Thanks for any advice,
SO> Stephen Offutt

While the Fluke meters mentioned by another poster are definitely Good
Things, they may be somewhat overkill for most of us.

Likewise, the clamp-on ammeter function is occasionally useful, but I
expect that most of us can live without it.  I very rarely find it
necessary to measure current, possibly because, without the clamp-on
meter, it involves breaking the circuit under test.  I have recently
bought a clamp-on AC/DC meter, so I may eventually change my opinion
:-)  Until fairly recently, clamp-on meters could only do AC
measurements, but DC-capable meters are now available for fairly
reasonable prices - but beware: most clamp-on ammeters are still
AC-only!

A frequent suggestion I've seen in an electronics newsgroup is to buy
several really cheap DVMs (Harbour Freight often sells them for
<$5.00) - you can go through a lot of those before you pay for a
Fluke, and they are adequate for most of our uses - and you won't get
too mad when you throw one overboard, or otherwise destroy it.

You will primarily want a meter to measure voltage and resistance (or,
more likely, continuity - a sort of "limited range" resistance
measurement).  Almost any DVM or analog meter will do that.

Although most meters these days are digital, I do find an analog
(moving-pointer) meter useful at times, particularly for finding
intermittent connections - it is easier to see the pointer move, than
to notice the change in the digital meter.


-- 
Peter Bennett, VE7CEI    Vancouver, B.C., Canada
Lien Hwa 28 (AKA Polaris 30) "Sea Spray"
GPS and NMEA info: http://vancouver-webpages.com/peter 
Vancouver Power Squadron: http://vancouver.powersquadron.ca