Multimeters

[sajohnson]

I am looking for a clamp-on multimeter that will measure up to about 600 amps DC and AC, in addition to the usual functions.

I also need true RMS, frequency, and min/max.

We use Flukes at work (DC Metrorail) but they are expensive. My personal meter is a basic Fluke. It is fine for routine use but I would like to measure high current. I have a Fluke clamp-on _AC_ current adapter but need DC also.

I am looking (try not to laugh too hard) at two Sears Craftsman meters -- their numbers are 82014 and 82353. They are relatively inexpensive ($100) and seem to have reasonable accuracy.

I am wondering if anyone has any experience with or knowledge of Craftsman meters, or could recommend something else.

I would really like to know who makes these meters for Sears so I can check them out.

 

[Thayne]

Those meters will probably work, but Fluke and others make separate clamp on accessories for high-amperage use. Only trouble is they can be expensive too. I would not buy a cheap meter because the jacks, switch, etc. are poor quality and won't last under regular usage. On the other hand, if you don't expect to use it everyday it would be ok. Also you won't feel so bad when it gets dropped or stolen--

 

[sajohnson]

Good advice Thayne, thank you!

I know Flukes are solidly built -- the equivalent of Motorola radios (which we also use).

As I mentioned, I did buy the clamp-on _AC_ current probe for use with my Metro-issued Fluke DMM. The problem is, even if I were to buy a _DC_ probe, the meter is not a 'True RMS' meter and will not measure frequency.

At my house, I use two Trace DR2424 inverters and 16 'golf cart' batteries for back-up power. Essentially a larger version of the UPS systems people buy for their PC's. I also have a generator (for long outages). Thus the need to measure high AC _and_ DC (especially DC) current, and frequency.

I don't anticipate using the new meter every day. In fact, I would probably leave it at home. I just want to make sure that the meters that Sears sells under their Craftsman name aren't useless toys.

If that is the case, I welcome suggestions for alternatives. Unfortunately, a Fluke clamp-on with the same functions is out of my price range for a meter that will only see occasional use.

 

[Thayne]

I'm afraid I didn't understand your post too well when I replied.(My fault)

Usually to read high dc amperages a calibrated shunt is used and the meter really just reads the voltage drop across the shunt, even tho it is calibrated in amps. I don't see why you care about "true rms" since you want to measure dc amperes? Or maybe you want to check the output of your inverters?
If the inverters don't put out a sine wave, then you do need a true rms to read it correctly

Anyway I have seen a lot of big (100 amp & up) shunts & meters at surplus places for a long time--cheap $5-10--

 

[sajohnson]

You're exactly right -- the inverters put out a modified sine wave.

The idea of spending $5 to $10 instead of $100 is tempting, but I like the idea of being able to just clamp around the conductor.

I did have some success determining the mfr. of the two Sears meters.

Sears #82353 is Extech #38389.

Sears #82014 is Right Touch (aka RTI) #82014 or 32-82014.