Maker Pro
Maker Pro

Tips on DMM for a newbie?

R

Rui Maciel

Jan 1, 1970
0
Can you spare any tips on DMMs for newbies?


Thanks in advance,
Rui Maciel
 
R

Rich Webb

Jan 1, 1970
0
Can you spare any tips on DMMs for newbies?

If it's the "on-off switch" type and not the "rotate to turn on and
select the function" type then get into the habit of leaving the DMM set
to a moderately high voltage range when you're finished with it.

That prevents those unfortunate learning experiences when one picks up
the DMM for the first time in a month intending to measure a voltage
source -- but it was left in an amperage range and <poof> blows the fuse
(if you're lucky) or the meter (if you're not).
 
M

Michael Black

Jan 1, 1970
0
Can you spare any tips on DMMs for newbies?
Buy a cheap one, and start using it. You'll then learn from experience
what is there, and get a better idea of what you might want in the way of
a better DMM. Someone already pointed out the need to be careful or
you'll wreck the meter, a beginner is far more likely to make mistakes
than one with experience, so buying a cheap meter means you won't lose
much if/when you do damage the meter. Or your interest in electronics
won't last, so you haven't spent too much on it by buying the cheap meter.

People could supply a list of "needed test equipment", but you have to be
the judge of what you need and can afford, but you won't get to that point
until you've actually started doing things. So when you can, it is far
better to start with used or cheap equipment, to get a feel for it, which
helps you to make an informed decision when/if you need something better.

I bought my first oscilliscope at an amateur radio auction for five
dollars, it was horrible, heavy and very old almost forty years ago,
but it gave me something to play with, which at that point was mostly what
I wanted a scope for. I learned the basics, and then learned how lousy
that scope was. That seems to be a better situation than being told
what you need, spending the money, and then not knowing what to do with
the scope.

Michael
 
R

Rui Maciel

Jan 1, 1970
0
Michael said:
Buy a cheap one, and start using it. You'll then learn from experience
what is there, and get a better idea of what you might want in the way of
a better DMM. Someone already pointed out the need to be careful or
you'll wreck the meter, a beginner is far more likely to make mistakes
than one with experience, so buying a cheap meter means you won't lose
much if/when you do damage the meter. Or your interest in electronics
won't last, so you haven't spent too much on it by buying the cheap meter.

Good point. Yet, there are tons of cheap portable DMMs on ebay which, besides external appearance
and what sort of battery they take, appear to lack any relevant difference. Are there any features
that I should look for?

People could supply a list of "needed test equipment", but you have to be
the judge of what you need and can afford, but you won't get to that point
until you've actually started doing things. So when you can, it is far
better to start with used or cheap equipment, to get a feel for it, which
helps you to make an informed decision when/if you need something better.

I bought my first oscilliscope at an amateur radio auction for five
dollars, it was horrible, heavy and very old almost forty years ago,
but it gave me something to play with, which at that point was mostly what
I wanted a scope for. I learned the basics, and then learned how lousy
that scope was. That seems to be a better situation than being told
what you need, spending the money, and then not knowing what to do with
the scope.

Thanks for the tip, Michael. You do make a good point.


Thanks for the help,
Rui Maciel
 
R

Rich Webb

Jan 1, 1970
0
Good point. Yet, there are tons of cheap portable DMMs on ebay which, besides external appearance
and what sort of battery they take, appear to lack any relevant difference. Are there any features
that I should look for?

A backlight for the display is nice to have.

A "true RMS" meter may be useful on the AC ranges. On the other hand,
the non-"true RMS" meters are set internally to convert average to RMS
for sine wave inputs so, as long as what you're measuring is pretty
close to a sine shape, the results should be close enough for most
purposes. If you really need a 0.1% or better RMS value for odd-shaped
waveforms, you'd probably already know.

Pick up a set of inexpensive banana to mini-clip (or alligator) test
leads. That lets you clip the DMM to the circuit's ground reference and
frees up one hand to do something else, or to clip one to ground and one
to a test point to leave both hands free while you adjust the gizmo.
 
P

Phil Allison

Jan 1, 1970
0
"Rui Maciel"

Good point. Yet, there are tons of cheap portable DMMs on ebay which,
besides external appearance
and what sort of battery they take, appear to lack any relevant
difference.


** That is because, essentially, there is none.

Are there any features that I should look for?


** You are just another boring, PITA fuckwit troll trying to make your
pathetic case of purchase anxiety over a $10 item into our problem.

Lemme tell ya - it fucking aint !!!!



...... Phil
 
T

Tom Biasi

Jan 1, 1970
0
Rui Maciel said:
Can you spare any tips on DMMs for newbies?


Thanks in advance,
Rui Maciel

Check the position of your probes every time. Many meters have no fuse in
the 20 Amp. position and trying to measure line in this condition will be
dangerous.

Tom
 
J

Jamie

Jan 1, 1970
0
Phil said:
"Rui Maciel"





** DMMs use probes - not tips.

Fuckwit.


... Phil
Jesus Phil, is our language that hard to comprehend or you guys
down under just don't get it?

P.S.

This should start a fire ball of two!

:)

Jamie
 
J

Jamie

Jan 1, 1970
0
Rui said:
Can you spare any tips on DMMs for newbies?


Thanks in advance,
Rui Maciel

Go to a harborfreight store, if you have one near by or order on line..

They have some that will be fine for first timers..
 
C

Cydrome Leader

Jan 1, 1970
0
Rui Maciel said:
Can you spare any tips on DMMs for newbies?


Thanks in advance,
Rui Maciel

here's a few tips

if the meter has a current range, it will act like a short circuit across
the probes. The meter will either blow a fuse or just burn out if you set
it to say a 250mA range and connect it to a large battery or an outlet.

In the volts range, it's much harder to break the meter

measuting the currents and voltages in a flashlight is usually pretty easy
and will let you learn what the meter is doing without breaking anything.

When a DMM acts weird, it may be time for new batteries, even if you think
they are still good.

if the meter has a diode check or continuity mode, it can usually run a
LED, at least if it's a red one.

measure whatever you can, like the output of power supplies that plug into
the wall or stuff like that. The more you do something, the more familiar
it becomes and the more sense it makes in the end.

Electronics is a hands-on activity.
 
A

amdx

Jan 1, 1970
0
Phil Allison said:
"Rui Maciel"



** DMMs use probes - not tips.

Fuckwit.


... Phil
ah Phil, sounds like you got up on the right side of the bed.
Mike
 
P

Phil Allison

Jan 1, 1970
0
"Jamie"
Jesus Phil, is our language that hard to comprehend

** Nope.

But the fuckwit OP needs to learn how to post a meaningful question.

Cos what he just post is not one.


..... Phil
 
J

Jamie

Jan 1, 1970
0
Bill said:
Harbor Freight - 7 function - DMM - $1.99

http://www.harborfreight.com/7-function-digital-multimeter-90899.html

Only problem is using it in direct sunlight which adds about 0.5 to
the reading.
Use in shaded light only.

-Bill
those things are sold and have been sold in a variety of inners with
all kinds of different names on them...

I still have some older ones I got that allows you to tie the
common of the bat to the common input. Makes for a quick hack display..
Most of the ones they have now won't let you do that, even though they
look the same on the out side. Different board.

I think I paid like $3.00 each from a tool flea market.
I got a arm full that day... They make good wheel wedges and
don't hurt so much when they fail!
 
F

Fred Abse

Jan 1, 1970
0
Check the position of your probes every time. Many meters have no fuse in
the 20 Amp. position and trying to measure line in this condition will be
dangerous.

They're the ones to avoid. I wouldn't countenance a meter with an unfused 20
amp range. There's a video on the Web (Link from the Gossen site, IIRC) of
a TÜV test on a DMM that'll make the point.

The Fluke 80 series (fused) alarms if you have a lead in either current socket with
a voltage or resistance range selected. Not totally foolproof, but it's
better than nothing.
 
T

Tom Biasi

Jan 1, 1970
0
Fred Abse said:
They're the ones to avoid. I wouldn't countenance a meter with an unfused
20
amp range. There's a video on the Web (Link from the Gossen site, IIRC) of
a TÜV test on a DMM that'll make the point.

The Fluke 80 series (fused) alarms if you have a lead in either current
socket with
a voltage or resistance range selected. Not totally foolproof, but it's
better than nothing.
Agreed, but since he is looking for a cheap one it is likely that he will
come across such a meter and I thought he should be warned.

Tom
 
Top