turning a PC or laptop into a multimeter

google will find several

also a working o'scope

baffles me why anyone would use a lap top for that purpose. Make a mistake and you have possibly lost a lot more than just a meter.

I've looked, of course, but don't really know what to look for in terms of usefulness to the field engineer and reliability. Fluke do quite a few meters with PC interface, and it's about time I upgraded, so I might go for one of those.

Don't tell me; you use an AVO 8, right?

That's another reason for my asking here; can they fry my laptop, or do they have a fail-safe function to head off that kind of, erm, inconvenience?

It depends what you want to spend. If it is for serious work and you can afford it, the Fluke 189 does it well, and is fully isolated so there is no risk to the laptop.

Just a plug (no pun intended) from a satisfied owner.

Ben Miller

The Metex M-3890D and M-3890DT (true RMS) multimeters have USB interfaces. They're available from Electronix Express . Price is $98/$116.

If you want a better quality meter, the Fluke 187 & 189 can connect to a PC using a special cable and Flukeview Forms software. This will cost about $500.

If you've got money to burn, you can get an Agilent 82357A USB/GPIB adapter ($500) and a 34401A 6-1/2 digit DMM ($1,200).

It's got a two-level back light display as well. £250 - £300 might sound a bit steep for a hobbyist to those who don't appreciate quality, but I think I'll manage to justify it. Thanks for the recommendation; it's perfect for my needs.

The Fluke 189 is about as far as I dare go, and just what I need. To be honest, I didn't realise that modern DMMs were so easily compatible with PCs. I thought I had to have a dedicated gizmo for that sort of thing. Thanks for your help.

No I do not have one of those. But I do have a couple of Simpson 260's. They rarely come out of the box any more.

Fail-safe, and electrical work is an double negitative, IMO. I have seen stupids, ( we all know them ) fry a Fluke scope meter USING the optical isolators. Not once but 3 times the guy did this. Even with the isolators I would be extremely nervous connecting my laptop to a electrical circuit. I like to take my measurements, then as your discovering download the information for the presentation or storage.

I agree. It is difficult to write down readings when you are wearing gloves, so I like the 189 because you can save a bunch of readings then either upload them or manually copy them down later.

I have only blown a Fluke meter once, and it wasn't in the field. I accidently got it across the high voltage in a microwave oven, which exceeded the 1000 volt input rating. The input protection circuit did its job, and for $100 Fluke repaired and calibrated it. That was about 7 or 8 years ago, so the price may have gone up.

Ben Miller

If you want to save a few dollars (or £) you could consider the 187. It is very similar, but It doesn't do stand-alone logging. I don't recall what the other differences are.

Also, if you find a little extra money, the magnetic hanger is one of the best accessories ever invented! You may not think so until you use it a few times, then you wonder how you ever got along without it.

Ben Miller

Observe the meter's maximum voltage ratings, particularly when measuring points floating above ground level. Make sure there are no more stringent limits when using any adapter. Or you'll turn your PC into a boat anchor faster than installing the latest version of Windows.

If you buy the Fluke 189, the communicatin link is optical. A very smart idea since it helps avoid blown up computer syndrome.

Charles Perry P.E.