I'm looking to pick up a clamp-on ammeter/multitester on ebay. Are
these ammeters AC or DC specific or do they read both as a matter of
course.

Marc wrote in
:


I'm looking to pick up a clamp-on ammeter/multitester on ebay. Are
these ammeters AC or DC specific

Yes. Most clampon ammeters are the AC model made for checking out AC house
wiring circuits.

There are DC models available, made from a device called a hall effect
generator by the way. You'll find these a little "pricey" for your
application, probably.

If you need to check alternator output or starter current, there are
several flavors of DC magnetic "ammeters", which amount to a magnet mounted
so it moves a pointer when it comes near the magnetism the alternator or
starter current produces. Auto parts stores have them and they are quite
cheap. They are useless for measuring some light DC load, but I suspect
you're not interested in measuring to 3 significant digits like the
"pricey" cousin can...(c;

or do they read both as a matter of
course.


No, they do not. The AC clampon is a simple current transformer where the
wire being tested is the primary winding (one turn). The DC model is a
solid state magnetic sensor device so sensitive you can measure the "DC"
magnetic field of the earth if you open up the jaws.

Amprobe makes a nice dual AC/DC one:
http://www.electrical-contractor.net...M-ACDC-400.htm
$146 from here.

http://tequipment.net/AmprobeClamp-onMeters.asp
Here's a whole bunch of models....

How about a more permanent one for, say, $62...digital.
http://www.backwoodssolar.com/Catalogpages2/meters2.htm
Look down the page to "Digital Panel Meters". With a 100A or 500A shunt he
wants $62...but, SHHHHH....don't tell boaters it wasn't $300 from a boat
place like Waste Marine!

Now, after you're through screwing around with the cheapies, get a Xantrex
and move up to the Big Boy's club:
http://www.affordable-solar.com/link-20-meter.html
It's a true AH meter you can preset your AH capacity into. I measures
volts/amps/AH/runtime-at-this-load, etc.

Affordable Solar is a great source of a wide variety of
panels/meters/regulators without the "marine markup" problem.
http://www.affordable-solar.com/affordablesolar/

For the really power hungry solar enthousiast, they have the 6KW AC power
system for a "hair" over $40K. I'm not sure this much solar is practical
on a sailboat, especially if the crew wants to sit out in the sun a little
without having to take the dingy ashore...(c; Hell, with 6KW of capacity,
you could replace the diesels and sails and go electric all the way.
http://www.affordable-solar.com/affo...d-tie-gts.html

--
Larry
Somehow having such capacity and FORCING the power company to buy my
surplus electricity, has always had a certain masochistic appeal to
me....(c;

"Marc" wrote in message
...
I'm looking to pick up a clamp-on ammeter/multitester on ebay. Are
these ammeters AC or DC specific or do they read both as a matter of
course.

As Larry says, they are specific.
If you are mostly interested in measuring DC currents on the boat I would
recommend one of the Hall effect units.
I bought a Fluke version on eBay for less, I think, than $100. Very
accurate and sensitive. Get a decent multimeter while you are at it. The
Wavetek handheld units can be obtained at good ebay prices, Fluke somewhat
more.