Do multimeters "wear out" after so many years? Fluke vs. Ideal, Wavetek??

[James Sweet]

You could, of course, simply use a parallel resistor to bring a DVM more
into line with a needle type. Something like 240k ohms for 240 volts.

The one area where I find an analog meter to really be easier is when you
want to monitor the relative amplitude of some varying signal, it's a lot
easier to visualize than jumpy digital numbers. For a quantitive value
though digital is SO much easier.

 

[Dave Plowman (News)]

The one area where I find an analog meter to really be easier is when you
want to monitor the relative amplitude of some varying signal, it's a lot
easier to visualize than jumpy digital numbers. For a quantitive value
though digital is SO much easier.

Better DVMs have a linear bar display to show you roughly the same thing.

 

[Sam Goldwasser]

A typical needle type VOM has a resistance of 20,000 ohms/V. So, on the
500 V range, it would have a resistance of 10M ohm. On higher voltage
ranges, the VOM would have a higher resistance than a typical DMM. Older
Simpson 260s have a 5,000 range with an input impedance of 100M ohm.

The one area where I find an analog meter to really be easier is when you
want to monitor the relative amplitude of some varying signal, it's a lot
easier to visualize than jumpy digital numbers. For a quantitive value
though digital is SO much easier.

Absolutely, or should I asy Relatively!

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[Sam Goldwasser]

Better DVMs have a linear bar display to show you roughly the same thing.

I find those pretty useless, not the same as a real needle.

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[Asimov]

"NSM" bravely wrote to "All" (05 Apr 05 01:10:53)
--- on the heady topic of "Re: Do multimeters "wear out" after so many years? Fluke vs. Ideal, Wav"

NS> From: "NSM" <[email protected]>
NS> Xref: aeinews sci.electronics.repair:44961

NS> I used a DVM to check for leakage on an AC line and got false
NS> readings. A 'real' meter worked better.


You have to use the proper UL defined leakage testing network to get a
meaningful DMM measurement on AC operated equipment. An analog meter
with low Kohms/volt sensitivity only approximates the required network
better than a 10Megohm DMM. In fact a 10Megohm analog will also give a
false reading.

A*s*i*m*o*v

.... Electrical engineers deal with current events.

 

[Dave Plowman (News)]

A typical needle type VOM has a resistance of 20,000 ohms/V.

Yup - that's common for a decent AVO on DC. But assuming no electronics,
1000 ohms/V AC is also common. Looking for the best pure non electronic
one I can find, this goes to 40,000 DC and 4,000 AC.

But for measuring home mains, 1000 ohms/V is fine. Stops those silly
readings caused by coupling of one sort or another.

 

[user_1]

I find those pretty useless, not the same as a real needle.

I'd think more people would be using those LCD Oscopes that are about
the size of a big meter these days.

 

[Dave Plowman (News)]

I'd think more people would be using those LCD Oscopes that are about
the size of a big meter these days.

Only if you're very rich, ;-)

 

[Michael A. Terrell]

Better DVMs have a linear bar display to show you roughly the same thing.

Have you ever had to adjust the bias or drive on a TV transmitter
with one of those? You would need new outputs before you ever got close
to the proper settings.

That "feature" is a piece of crap in the real world when you need to
see a dip or peak that's only a couple needle's widths apart.

 

[James Sweet]

Better DVMs have a linear bar display to show you roughly the same thing.

Mine has one of those, it's really not very useful though, an analog needle
has *far* higher resolution and reacts more quickly.

 

[James Sweet]

I'd think more people would be using those LCD Oscopes that are about
the size of a big meter these days.

I've used those a couple times and really don't like them much, they cost an
arm and a leg and the performance is nowhere near that of a good analog
scope.

 

[Michael Black]

Mine has one of those, it's really not very useful though, an analog needle
has *far* higher resolution and reacts more quickly.

As I've said, the solution would be to put a tiny analog meter inside
the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

Michael

 

[James Sweet]

As I've said, the solution would be to put a tiny analog meter inside
the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

If they included an analog meter movment it'd probably be too small to be
useful and add too much to the cost. Easier to just keep an analog meter
around for the situations that need it. Digital is adaquate for most things.

 

[Dave Plowman (News)]

As I've said, the solution would be to put a tiny analog meter inside
the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

Trouble is including an analogue meter would *vastly* increase battery
consumption.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

Agreed they're not as good.

I remember seeing one which had an LCD analogue meter complete with needle.
But I don't know if it had the same ballistics as a 'real' one.

 

[Mark D. Zacharias]

Butting in....

So what are you guys' favorite meters?

I mentioned my Beckman 223 died. I always liked the Fluke 77, and don't need
special stuff like frequency counter, computer connectivity or the like.

I do need it to have a tilt base and be heavy enough that simply moving
leads around won't jerk it around or knock it over.

I can pick up a good condition 77 on eBay any day for around 50.00 or so,
but that's an almost 20 year old model.

Is the Fluke 77 mark 3 any good? The 87 seems a bit big for my purposes,
though I suppose I could get used to it. What other models would you all
recommend?


Mark Z.

 

[Dave Plowman (News)]

Is the Fluke 77 mark 3 any good? The 87 seems a bit big for my purposes,
though I suppose I could get used to it. What other models would you all
recommend?

I've got a 179, and am very pleased with it. Does have frequency counting
though - and temperature.

Auto ranging and hold with min max.

Only think I dislike is the near rigid test leads. ;_)

 

[Mark D. Zacharias]

I've got a 179, and am very pleased with it. Does have frequency
counting though - and temperature.

Auto ranging and hold with min max.

Only think I dislike is the near rigid test leads. ;_)

The 73 looks pretty nice - and doesn't taper down towards the base like the
77 III, which looks kind of unstable to me.

Mark Z.

 

[Sam Goldwasser]

If they included an analog meter movment it'd probably be too small to be
useful and add too much to the cost. Easier to just keep an analog meter
around for the situations that need it. Digital is adaquate for most things.

Some more specialized measuring instruments like laser power meters do
have both. The analog and digital displays share the same space as in
Coherent's Fieldmaster:

http://www.cohr.com/Lasers/index.cfm?fuseaction=show.page&id=254&loc=830

That's been around in essentially the same form for at least 15 years.

I think they tried to do away with the delicate analog meter at one point
in favor of a bargraph display but then went back to the analog meter.

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[JazzMan]

Butting in....

So what are you guys' favorite meters?

I've got a Fluke 87 and an 88, which is just an automotive
oriented verson of the 87, and I like them both. With
10M Ohms input impedence I can measure O2 sensor voltage
directly, use the analog bar to see rich/lean status, and
use the averaging function to study trends. I've had my
87 for more than a decade and the 88 for nearly that long.

JazzMan
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[James Sweet]

The 73 looks pretty nice - and doesn't taper down towards the base like the
77 III, which looks kind of unstable to me.

I do like the 73, I really don't like that newer tapered design, still can't
figure out why they did that, it's just not as comfortable in my hand.