im pretty clueless about them, but i need a digital multi-meter with 10 mega-ohm impedance. can someone recommend me one? the cheaper the better of course. i was looking at a few greenlees(fluke is too much). if anyone can find one off grainger.com id appreciate it.

thanks, brian

 

Why the need for 10 meg ohm impedance? What are you trying to test or check?

Anyway for a digital meter, how about $3?

There is a Harbor Freight in Charlotte according to the web page. They have this on sale for $3:

http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=90899

this one for $10:

http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=30756

http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=92020

This one is $13 and will measure up 20 meg ohms:

http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=90939

I have one of these cheap HF meters I keep upstairs, when I need to make a quick check of something I don't want to have to run to the basement and get my Fluke out of the toolbox. For everything I have needed it for, it has been fine.


Radio Shack also has a range of multimeters from $20-90.

Dennis

 

you can get one at home depot for like $20 that reads all the way to infinite impediance.

Its red with a clamp top, and a round black dial.....can't remember brand off the top of my head...

John

 

Just because it reads "Inf" or whatever doesn't mean it can actually reading infinite resistance (if there was such a thing). It simply means the meter has encountered a resistance higher than its measuring capability. Years ago I picked up a semi-cheapy metere from Radio Shack (of all places)... the thing is surprisingly good with a lot of features. Measures up to 2 Gigaohms.

You generally don't pay for range, you pay for accuracy.

 

yup, i have a meter i picked up on closeout from the Shack 10+ years ago for like $25. it ticks along just fine and seems pretty reasonably accurate for the money. i think it's max resistance reading is 30 Mohm.
it's so old though that it doesn't even auto-range... works just fine for me. makes me think about what i'm measuring.

 

I assume its infinite resistance.....it is an ohm sign (Omega) with an infinity sign over it. It is just one of like 6-8 different measuring modes.

John

 

Like MacGyver said it: How much accuracy do you need?

Personally, I have a $450 meter. Another guy i work with bought one on eBay for $5. He doesn't need the accuracy nor would he understand the difference in his job. Mine involves finding noise related issues and tuning analog circuits quite often. What's your need?

 

My $3 HF meter may not be nearly as accurate as the Fluke in the toolbox, but it is well worth $3 not to have to always go get the Fluke to see if "this AA battery is good" or "is the circuit breaker to this wall outlet off?" or "is this a +12v power lead or ground?".

Dennis

 

Y'all missed it. He doesn't need to measure 10 mega ohms, he needs a meter with an input impedance of 10 megs or more.

Fortunately, most digitals will fit that bill, but maybe not the $3 one. I'd say check the specs in the manual but it might not have one, or if it does I don't know if I'd trust the book to be accurate. Likely to have been printed for last year's $2 meter and they didn't feel like reprinting them.

 

I think I got you all beat (except for the $450 jobbie). I have an AC-powered multimeter that's digital. The kicker is, it uses nixie tubes for the display.