Go Down

Topic: Good quality cheap multimeter (Resolved) (Read 1 time) previous topic - next topic

SwissAndOr

Mar 06, 2014, 04:20 am Last Edit: Mar 08, 2014, 04:41 am by SwissAndOr Reason: 1
Do you guys know any good quality cheap multimeters for use with the Arduino? Also, is digital or analog better for this sort of stuff? I'm new to Arduino and I hear multimeters are very usefull. Thanks.

pegwatcher

I would recommend digital. Generally more rugged, easier to read. There are many for around 20 bucks that should do anything you need.
Craftsman: http://www.sears.com/craftsman-multimeter-digital-with-8-functions-and-20/p-03482141000P?prdNo=1&blockNo=1&blockType=G1
Home Depot: http://www.homedepot.com/b/Electrical-Electrical-Tools-Accessories-Electrical-Test-Meters/N-5yc1vZboff?cm_mmc=SEM|THD|VF&skwcid=AL!3360!3!20815777477!e!!g!!digital%20multimeter&ef_id=Uw2qmAAAAcDekrtm:20140306042426:s
And radio shack has some.
I'm not a complete idiot. Some parts are missing.

polymorph

Do yourself a favor, only get a meter that is autoranging.

And I strongly suggest that you do NOT buy any Cen-Tech meters. The last five I bought there were filled with solder balls and bits of wire. Sad, because they used to have some decent cheap DMMs.

I bought a Craftsman meter from Sears a few years ago. It just started malfunctioning, indicating 85Vac on a 120Vac circuit even after replacing the battery. I opened it up to find several capacitors with the heat shrink labels half off and one missing the label entirely. It was NOT inside. Additionally, whomever had trimmed the 10A shunt by half cutting through it had taken a big chunk out of several nearby parts. Several solder balls, way too much solder on the joints.

This was NOT a cheap meter. Very disappointing.
Steve Greenfield AE7HD
CET Consumer Electronics and Computer
Please don't read your attitudes into my messages

cr0sh


And I strongly suggest that you do NOT buy any Cen-Tech meters. The last five I bought there were filled with solder balls and bits of wire. Sad, because they used to have some decent cheap DMMs.


You buy them? I always wait for the "free" coupon...

That said, I've never had a problem with them - at least for the purpose of using them as "throwaway" meters - when I am doing something where I just need an extra readout, or where I think I might kill my "better" meter. For around the house stuff, quick continuity checking, and automotive work - they seem to work fine for me.

That said - I might crack open one my "newer" ones and see what the build quality looks like (I expect to be disappointed).
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

zoomkat

For $30 or less, full feature multimeters are available. Auto ranging is nice. I've got a bunch of the harbor freight multimeters like below and have never had any problems with them. The only thing they lack that is nice is the "beep" continuity function.

https://www.google.com/search?q=multimeter&num=100&lr&as_qdr=all&source=univ&tbm=shop&tbo=u&sa=X&ei=PBYYU4aGGcb80AGS8YGADg&ved=0CCcQsxg&biw=1108&bih=628#spd=0

Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

SwissAndOr

Thanks! I don't have time to look at them now but certainly will when I get home.

fungus

I've got two $15 multimeters. Every time I compare them to a big expensive one I get about the same reading. That's good enough for me.

Get one with a buzzer for continuity readings. Autoranging is nice but not essential.

PS: Get one with a fuse that's easy to change otherwise you'll spend a lot of time wondering why the ampere readings are weird. Oh, wait, there's no such thing at any price. You always have to undo at least a dozen screws and lever it apart to get at the fuse. Look for one that has a visible indicator for "blown fuse" instead. Oh, wait...


No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

polymorph

That cheapo (or free) Cen-Tech is the worst offender. I found strings of solder and bits of wire in places where a slight shift while measuring house voltage could cause the meter to turn into a small flash grenade in your hand.

Even using it only on low voltage, low power circuits, I won't trust one. Some of the Cen-Tech's I recently bought had problems right out of the package. Our maker space had about 8 donated when we started it, and all have failed partly or completely.

Cheap tools cost more money.
Steve Greenfield AE7HD
CET Consumer Electronics and Computer
Please don't read your attitudes into my messages

InPhase277

Cheap multimeters are hit and miss. Sometimes you get one that is OK, other times they are crap out of the box. And NEVER use a cheap meter for work that can deliver more that a few amps at low (<50 V) voltages. For one, you can't trust the CAT ratings on them. And two, it could fail to read at the wrong time and leave you taking a dirt nap.

In summary, for Arduino-level work, the meter you get at the gas station for $1.99 may be OK. But if your're troubleshooting a 480 V motor control in a factory, get a Fluke. It's the difference between life and death.

polymorph

Quote
In summary, for Arduino-level work, the meter you get at the gas station for $1.99 may be OK. But if your're troubleshooting a 480 V motor control in a factory, get a Fluke. It's the difference between life and death.


As someone who has worked in electronics for many, many years, I agree. Is your life only worth $20?

However, for Arduino type measuring, make sure you get a hit, not a miss. I've seen many technicians and amateurs chasing their tails for hours because of bad test equipment.

I've been happy with this little Tenma $20 meter, and a few more $20 meters.
http://www.mcmelectronics.com/product/72-10400?green=11458509902

But I also have owned a Fluke (sadly, died a quiet death) and now own one of these:
http://www.circuitspecialists.com/dm620.html
Steve Greenfield AE7HD
CET Consumer Electronics and Computer
Please don't read your attitudes into my messages

CrossRoads

I've got an Extech EX330 and have been very pleased with it.
http://www.extech.com/instruments/categories.asp?catid=48

You can find it for well under the $60 list price, I see $45 in google ad listings.  The temperature probe has come in handy for measurements of our toaster oven for reflow soldering.

Seems to have done well in online reviews as well:
http://www.extech.com/instruments/press.asp?pressid=06072010
http://www.adafruit.com/products/308
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

elac

I use the MS8268 for under $30
If you need inductance and temp. readings then:
MS8269 for under $40

It's all about the skills

danb35


PS: Get one with a fuse that's easy to change otherwise you'll spend a lot of time wondering why the ampere readings are weird. Oh, wait, there's no such thing at any price.

Suggest you look at a Fluke 27.  I picked one up (used) for around $50 US through eBay.  When you open the battery compartment (two 1/4-turn latches), the fuses are accessible.  They're expensive to replace due to their construction, but they're easily accessible.  A number of other Fluke meters have easily-accessible fuses, but they're considerably more expensive.  The 27 is also built like a brick, autoranging, and should do everything you'd need to do with an Arduino.

Not sure how much you'd actually use the current measurement with Arduino projects, but it's there.

fungus


Not sure how much you'd actually use the current measurement with Arduino projects, but it's there.


I do quite a few battery powered projects with AVR chips (eg. Tiny85). I use it a lot for that.

Arduino Uno? High power LEDs, etc. (on the 10A scale)
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

polymorph

Read specs carefully. I just bought and returned a meter from Lowes Hardware. Returned because the 10A range has a duty cycle of 30 seconds on at 10A, 15 minutes off!! Unacceptable.

The other end of the scale (oops, a pun!) is measuring microamps when trying to optimize circuits to run from batteries.

My cheap meters generally don't have current measurement scales. With them, instead I have 0.1 ohm 1% resistors I wire in series and measure the voltage, and have used current shunts consisting of a length of 16 gauge wire. My main expensive meter normally has the capability to measure from microamps to 10A.
Steve Greenfield AE7HD
CET Consumer Electronics and Computer
Please don't read your attitudes into my messages

Go Up