Scopemeter

[ATSman]

I am looking to buy a scopemeter and have seen the following Fluke models on eBay $400-1200 range:
97, 99B, 123, 105B, 192B, 199C. I would like to hear from anyone that owns or has used
any of these or other models and can recommend one over the other (i.e. pros & cons)
Pls don't send me links for the specs on these as I am more interested in your hands on experience and can always access that.
I have used the model 43B ten years ago but am sure they have improved since then.
Tks in advance.

 

[GeorgeB]

123 owner/user

123 owner/user

I have a 123 which meets my needs fine. MINE, and from the links I see via Google and services in ebay, many, has very poor battery life (it must have been turned on in the case, a poor push button for power design) and "sensitive" screen with many dead rows.

There are non-Fluke products out there at significantly better prices, ESPECIALLY if you are willing to be tied to a 120V power source.

 

[ELA]

I have used the 190 series in the past ( over 7 years ago now so a little foggy memory).
I thought it was a great tool. As stated earlier you can buy a cheap Rigol scope if you do not mind needing an AC connection. I have used Rigols and they are indeed cheap.

The thing I liked most about the 190 series was being free of an AC connection. It is really handy when taking AC line measurements and not having to worry about isolation.
The 190's with deep memory storage had some good tools for the PC that allowed you to log data and upload via a serial connection that was very handy.

 

[ATSman]

Thanks for your input guys!
I was hoping to get more responses than this :happysad:

 

[Besoeker]

Thanks for your input guys!
I was hoping to get more responses than this :happysad:

Depends on what you want to use it for.
I had a Fluke 123. It did most of what I needed it for. Battery life was a bit of an issue.
All I can suggest is that you beware of spending too much money on features that you don't need or are never likely to use.

 

[gar]

130118-1733 EST

I have no suggestion on a particular instrument.

I think it would help getting replies if you defined what kind of signals you want to measure (including whether voltage, current, power, energy, average, peak, RMS, spectrum, log-linear, log-log, frequency, period, derivative, integral, etc.), the kind of problems you may encounter, price level, weight, floating off of ground, environment, etc.

I can get certain information from an analog phosphor based scope that is not possible with a digital scope, and vice versa.

.

 

[Besoeker]

130118-1733 EST

I can get certain information from an analog phosphor based scope that is not possible with a digital scope, and vice versa.

Slightly off the main topic but I'd be interested to know what information you get from the analogue CRT scope that you can't get from a digital scope.

 

[gar]

130119-0817 EDT

Besoeker:

If I take a waveform, random Gaussian for example, and apply this to the vertical axis, then the intensity of the image vs vertical displacement is a measure of the probability density distribution curve of that signal.

Related to this I had a high resolution rotary encoder and other components in a system to measure gear ratio. Ratio measurements were erratic. The plant had a digital scope that we used to look at the signal at several points in the system. This was quite a few years ago and not a more modern digital scope. Could not easily see where the problem was. Suspected the encoder. Changed it and the problem was corrected. When I took the encoder back to the shop and looked at it with an analog scope the intensity variation immediately identified the problem. Lots of memory in a newer digital scope would have allowed an alternative means to use the digital scope to find the problem.

Also could have used other means with the old digital to find the problem. But when you are on a production line and hold up production to run experiments it gets to be a question of the quickest solution. Replacement, trial and error, in this case was the likely quickest. Then study the problem later.

.

 

[Besoeker]

Besoeker:

If I take a waveform, random Gaussian for example, and apply this to the vertical axis, then the intensity of the image vs vertical displacement is a measure of the probability density distribution curve of that signal.

Not something I would have thought of. But if truly random, would it have a probability? If you play roulette there ought not to be a variation in the probability between the numbers coming up.

Related to this I had a high resolution rotary encoder and other components in a system to measure gear ratio. Ratio measurements were erratic. The plant had a digital scope that we used to look at the signal at several points in the system. This was quite a few years ago and not a more modern digital scope. Could not easily see where the problem was. Suspected the encoder. Changed it and the problem was corrected. When I took the encoder back to the shop and looked at it with an analog scope the intensity variation immediately identified the problem. Lots of memory in a newer digital scope would have allowed an alternative means to use the digital scope to find the problem.

Also could have used other means with the old digital to find the problem. But when you are on a production line and hold up production to run experiments it gets to be a question of the quickest solution. Replacement, trial and error, in this case was the likely quickest. Then study the problem later.

Yes, systematic substitution....

 

[gar]

130119-1355 EST

Besoeker:

For any waveform, random or periodic, there is some probability that the signal will be above some level. That test or interrogation level can be adjusted relative to amplitude and from measurements or theory a probability curve can be developed of the signal being above that level, or you might do it below the level.

If instead you look at a small delta segment of the amplitude, then you can develop a probability density distribution curve.

See http://en.wikipedia.org/wiki/Normal_distribution both density and cumulative curves are shown.

.