Multi Meter Thread.

[gunsimon]

In the past few days I have been seeing a lot about multi meters. So I figure now that we have a drivers section I would create a thread (hopefully to be stickied) about multi meters....

Multi meters come in many form and many prices. I will discuss my meter because it is one i am familiar with. Also because it has all the necessary settings for our hobby.

I have a snap-on digital multi meter that is manual ranging. i am not a fan of auto ranging because i get confused sometimes. the settings relevant to the lasing hobby are:

dc miliamp (dc ma) setting (you will use either the 200ma or the 2a or the 2000ma setting, depends on drivers desired output and wording on the meter)
dc amp (dc amp) setting
continuity setting
diode testing
dc volts
dc miilivolts (dc mv)
ac volts.
YOU WILL WANT A SCREEN RESOLUTION OF ".000"
You will also want some test leads that have really small alligator clips at the end, or some pointer ends that let attachments screw on.

Mine was $150.00 but snap on lets you pay weekly. there are many others with the same capabilitys for way cheaper.

The dc ma and dc mv settings let you test the driver out put. there are tutorials on this so i won't get into that. If i missed any thing feel free to hit me up.

 

[Cyparagon]

there are tutorials on this so i won't get into that.

I think this about sums up the thread.

 

[Benm]

There is endless content on them really. Personally i like to have a true-rms AC range as well, but for most laser applications that adds very little.

If you come across great deals i'd be happy to hear about it.

One thing to be a bit wary off is the 10/20 amp range: they often can sustain full current only briefly, which could be a problem when measuring high power (several amp) laser diodes. Also cheap leads are problematic here, i've seen them looking reasonably normal from the outside but with very little conductor on the inside (resulting in an ohm per meter or so).

It's best to put a shunt in circuit and measure voltage across that for guaranteed continuity in any case, but perhaps it's a useful warning for beginners.