What's essential on a multimeter?

[pearlyred]

Hi guys. I'm looking at buying a multimeter as I guess I'm gonna need one pretty soon. Being new to electronics I dont wanna go and spend heaps on something I dont know how to use though (overkill).

If i go for a basic (reasonably cheap) multimeter, what are the essential functions/stats it should have?

Your advice greatly appreciated.
LS

 

[Klaus]

LS, the cheap basic digital multimeters do all have the 'basic' functions you would expect from a "multi" meter :wink:

Nice little extra's are:

a buzzer to check continuity in circuits

the ability to measure Amps in DC and AC - some only do DC

a low Ohm range ( <100 ohm)

transistor checking socket

display hold facility

readout reversal ( for using the meter 180 deg rotated)

temperature probe

these suggestions are in no order of priority, no cheap meter will have all of them anyway
you choose what you want for your money :?

Klaus

 

[Someone Electro]

I got myne for $45 and along whith basic functions its has:
-Feqency
-Transisotr test
-Capacitence meshurment
-Temperature
-Auto thurn off after (So if you forget to thurn it off it will thurn of itself to save batery life)
-It came whith an ruber case that is also an stand.(I find this realy useful)

 

[gjpollitt]

I got myne for $45 and along whith basic functions its has:
-Feqency
-Transisotr test
-Capacitence meshurment
-Temperature
-Auto thurn off after (So if you forget to thurn it off it will thurn of itself to save batery life)
-It came whith an ruber case that is also an stand.(I find this realy useful)

The one I bought recently with the same features as above only cost me £15 brand new, a bargain

 

[panic mode]

voltage, current and resistance are the most important ones but
the more it can do the better. capacitance and frequency are really
nice to have.

imho transistor tests on multimeters are useless, or in other words
i would need to see one that works good. the ones i checked simply
measure Ice current and display result as gain. if you have a leaky
transistor it will show good results, you can stick resistor to C and E
terminals (with nothing connected to B) and it will still show gain.
that's very stupid. fortunately it is very easy to build your own
transistor, SCR zener etc testers...

 

[Dean Huster]

The big question that hasn't been asked is, "What are you going to use the meter for?"

If you're doing industrial maintenace involving high-energy circuits, you'd better maked darned sure that regardless of any other functions of the meter that it's rated for Category III or Category IV so that it doesn't blow up in your face if something isn't done right when using the meter (like measuring the number of ohms on a live 440V 3-phase line).

If you're going to be working with 8-bit ADCs and DACs, any DMM will work fine. But if working with 12-bit ADCs and DACs, you'll need a meter with good accuracy, at least 0.01% since a 12-bit DAC/ADC resolves to 0.024%

If you're doing just general troubleshooting of solid state circuits, you may need a simple meter with the addition of a transistor test function.

If you're working with high-end audio, you may want a simple DMM for troubleshooting and spend your money on a decent AC voltmeter instead.

Note that everyone is going to have a different opinion concerning the best meter, and I'm no different, of course. But I tend to ease off into spending your money on simple, high quality meter (usually a Fluke) rather than an inexpensive meter that has 76 functions/ranges. You can find meters out there than can measure DC voltage, AC voltage, DC current, AC current, resistance (those are the minimums for any meter), frequency, capacitance, inductance, temperature, transistor hfe, white cell count and who know what, most on several manual and/or automatic ranges. Remember that the term "multi" in the description of any test equipment usually means that there's some give-and-take in accuracy, safety and reliability to give you all those features. At the schools where I've taught, it's always those fancy, cheap meters that are tossed into the "broken" box while the simpler meters keep on chugging.

So, don't get caught up in all the "bells and whistles". Just because that fancy graphing calculator has 784 functions doesn't mean that you're going to probably use not much more than 14 of them and use the other just for "playing".

Dean

 

[zevon8]

One thing I would add about the continuity test found on meters... many use a very high-pitched , low output piezo that can be difficult or impossible to hear in a noisy environment, or if you have any hearing loss. I have enough high-frequency loss in my hearing that I am unable to hear some of these meters.

Also, some of the lower priced "do-everything" meters have rotary switches with 30 or more positions. Being a mechanical device, they are easily damaged or can cause errors if not handled with care. Don't go quickly turning them from one position to another if you want them to last.

For those old enough to remember, this was the reason you were yelled at if you raced through the channels on an old rotary tuner on a TV set. The tuner drum with its myriad of connections didn't like this treatment either

If you choose to get an "auto ranging" meter, make sure you can set ranges manually, or lock a range as well. Sometimes if you are measuring a varying voltage close to a range limit the meter display will just be jumping back and forth from range to range, never displaying any intelligent information.

Edit- Dean types faster than I do.. :lol: I agree with his points, get a meter that does a good job of what it will be used for 90% of the time. The other features are a bonus, as long as they don't compromise the basics. I find myself using my Fluke 12 more than my other more expensive meters, because the majority of the time I just want a quick diode test or voltage measurement. The other meters come out when the going gets tough, or greater accuracy is required.

 

[Nigel Goodwin]

One thing no one seems to have mentioned?

ANY METER IS BETTER THAN NO METER 8)

 

[eblc1388]

And most of the meters on sale today use pads on a printed circuit board as contacts for the meter selector. Gone are the days of a proper ceramic selector wafer switch.

 

[drrogla]

I have one of those... My dad got it as a gift from his brother more than 30 years ago(by the way its analog :wink: ). His brother brought it to slovenia(part of former yugoslavia) from germany, because in those days it was difficult to get electronic parts and tools here. He told me it came in pieces as a kit and he had to build it himself.
I can post pictures....

 

[pearlyred]

It will just be used for home hobby type stuff, playing with PIC's and my pc etc.

You've given me a good idea of what to look for, thanks guys.

 

[Someone Electro]

Just make shure you will use the fetures.Dont go for an ferure that your not going to use.

I found the temperature probe qite useful wen doing stuff whith power transistors to mehure at what temperature the transistor is runing.Wen its to hot to hold in your hand dosent mean the transistor will burn out.