Need advice in selecting an oscilloscope for general automation work

[Div_by_zero]

Wanting to buy my first oscilloscope. Need some help here, the choices are overwhelming. What bandwidth and what sampling rate would be appropriate for an "automation guy"? Also, what brands are good? I'm willing to send up to $1,000, but would like to explore the $500 region first. Also, what probes?  It is my understanding that probe quality is critical. Some things I would want to do with it, not limited to:   -0-10V and 4-20 mA analog signal voltage analysis (noise) -AC power waveform analysis (up to 480 VAC) -DC power supply quality analysis -inverter output waveform analysis   Thanks for any help!     Edited December 14, 2015 by Div_by_zero

[Mendon Systems]

It is going to depend a LOT on exactly what you mean by automation. If you are just looking at analog signals you can probably get away with a lot less bandwidth that monitoring things like encoder signals. Some of the Scopemeter type devices can be really handy for simple stuff but are not really very fast or accurate. I managed to pick up a used 4 trace 350mhz Tektronics a few years back that covers almost everything that I have ever needed, but it isn't a storage scope which would be handy to have at times. For the amount that I actually use it, I couldn't really justify anything more elaborate. Edited December 14, 2015 by Mendon Systems

[Div_by_zero]

Hi Mendon, Yes, sort of figured it was going to heavily depend on whether or not I'll be using it for communications. I'd say at first, it will not be used for communications at all, but if it had the ability to do at least some of that, it wouldn't necessarily be a bad thing. I gather that the scopemeters, even the nice ones like the Flukes, are really only good for things like determining if you're feeding a $20,000 motor with garbage power or not while in the field...  

[jawolthuis]

I use a Fluke 123. I know that is above your price range, but I got mine for ~$400 on ebay. If you keep your eye out, then you can find a deal on one.

[Div_by_zero]

Hi Jawolthuis, In your opinion, how does that Fluke compare to the benchtop models?    

[jawolthuis]

I have an older B and K benchtop...  I have not had it out in years, it is about 2' deep, and 18" wide... I really like the Fluke because it is so handy to haul around. I also found a used hard plastic case for it so that I can throw it in my truck and not worry about it. Here is a nice one on ebay (No it is not mine, or anybody's that I know): http://www.ebay.com/itm/Fluke-123-Oscilloscope-20-MHZ-ScopeMeter-Digital-Multimeter-with-Box-/291634628368?hash=item43e6c74710:g:zYsAAOSwnH1WZwrr

[rdrast]

I have both a Hitachi, and a Tektronix, both are excellent.

If you are looking on a budget, this is a great place for used/reconditioned gear.

I'm older, and MUCH prefer a CRT scope to the digital ones, at least until you get into the $2500 range.

If you plan on looking at high voltage (drive outputs for example), be prepared to spend some money on a decent differential isolation probe.

[DanW]

I bought a Rigol DS1102E benchtop scope a couple years ago for $350 on sale: 100MHz, dual channel, separate trigger channel, to use for looking for noise on 4-20mA or RS-485 lines.  Came with a couple light duty probes and a carry case (carry case was separate option, an incentive from the distributor)

It is AC powered, no battery power available, so one needs an AC source or a UPS battery back-up (I had to drag a desktop PC UPS into the field once for power).

There is a public software hack (Youtube) to increase the sampling rate from 50MHz to 100MHz, which is the difference between the 1052 and 1102 models.

I only bring it out about once a year and I find I have to think about how to use, compared to the analog scopes I had a work over the years, but it comes back fairly quickly.

It uses a National Instruments program for remote screen views.

DS1052E (50MHz version that is now replaced by DS1102 100MHz, apparently a firmware difference, not a hardware difference)

There is a comparison review of the 2072E (at about $800) vs the 1052/1102 models, that might be worth the 30 minutes if you're spending your own money.

Dave compares DS2072 or the DS1052E
https://www.youtube.com/watch?v=_TSr9nFN1GU

Dave's Opinion of the really cheap USB scopes (9:04)
http://www.youtube.com/watch?v=Xh9FNRpta9s

Dave's Review of DS1052E
http://www.youtube.com/watch?v=kdjpbWLi7UI

 display is 800x480; min 70MHz on the DS2072, 2G samples/sec vs 1G samples/sec, boxcar averaging
  150MHz passive probe is std, anti-aliasing mode (not on the 2052E)  14x the memory, segmented memory control  

TKJ review, DS1052E modified to DS1102E
https://www.youtube.com/watch?v=B0ajIBb4EU4

There is a series of really good video tutorials on YouTube:

Rigol DS1052E #1 intro with remote control (8:08)
http://www.youtube.com/watch?v=Q7KnDoL8cCM&list=PL5CB18FC5F6902CC7

Rigol DS1052E #2 Squarewave & Probe Comp (9:59)
http://www.youtube.com/watch?v=rLkcwmfez04&list=PL5CB18FC5F6902CC7

Rigol DS1052E #3 Vert & Horz controls (9:21)
http://www.youtube.com/watch?v=FeYl3v3gFh8&list=PL5CB18FC5F6902CC7

Rigol DS1052E #4 Trigger Controls (9:36)
http://www.youtube.com/watch?v=7K1C1M1X2NU&list=PL5CB18FC5F6902CC7

Rigol DS1052E #5 Alt Sweep (7:42)
http://www.youtube.com/watch?v=08zgRXY0OHM&list=PL5CB18FC5F6902CC7

Rigol DS1052E #6 Math Functions (9:47)
http://www.youtube.com/watch?v=m1cHW2JM1TQ&list=PL5CB18FC5F6902CC7

Rigol DS1052E #7 Math Functions, con't. (6:19)
http://www.youtube.com/watch?v=HwkkgYdHRqU&list=PL5CB18FC5F6902CC7

 

[Div_by_zero]

Well, turns out I went with a Rigol 1054Z.  I did the upgrade thing via a web site, it's now essentially an 1104Z.  Pretty cool.

This is my first scope, have a couple very basic questions:

1.  The scope is rated for 300 V.  If I use a stock probe set to 10x attenuation, can I safely measure a 480V waveform?  I assume I need a high voltage probe for this?  Don't worry, I won't even try this until getting a solid answer.

2.  When trying to "zoom in" on part of a waveform by turning the volts/div down, I often find myself getting lost.  Also, when cranking the vertical position to try to get back to the trace, I'll often get a "parameter limited"  What am I doing wrong here?

Thanks for any help.