Author Topic: Rigol DS1054Z and slow processes  (Read 794 times)

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Offline jkprg

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Rigol DS1054Z and slow processes
« on: October 12, 2017, 02:20:44 PM »
Hi!
I'm about to buy my first scope. And it's gonna be DS1054Z probably. I just want to know if it's possible to measure/get characteristic of slow processes like charging and discharging batteries for instance. Automatically of course  (kind of time-lapse during few hours). Is that possible?
Thx
 

Online Dubbie

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Re: Rigol DS1054Z and slow processes
« Reply #1 on: October 12, 2017, 02:21:38 PM »
You could use a script to do it but it's kinda the wrong tool for the job. More appropriate would be a logging multimeter.

Much better accuracy and resolution.
 

Offline technogeeky

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Re: Rigol DS1054Z and slow processes
« Reply #2 on: October 12, 2017, 06:21:31 PM »
Hi!
I'm about to buy my first scope. And it's gonna be DS1054Z probably. I just want to know if it's possible to measure/get characteristic of slow processes like charging and discharging batteries for instance. Automatically of course  (kind of time-lapse during few hours). Is that possible?
Thx

Other people answered the question "Is it a very good way to measure slow processes ... with a DS1054z?" The answer to that question is probably no, but it is certainly possible.

The experimental setup:

  • 12V sealed lead acid battery (UPS battery)
  • DPS5005 (buck) power supply
  • 25W constant current load
  • Rigol 1054z

The settings:
  • The load was set to draw 12.00 watts.
  • CH1 is watching the voltage of the battery, DC coupled, 2.00V/div
  • CH2 is watching the voltage of the battery, AC coupled, 50.0mV/div (to watch the noise fed back to the battery from the DPS5005)
  • I am using the Rigol Bildschirmkopie software to take a screen capture every 10 seconds over USB
  • I discard 5/6 screen captures to make the displayed GIF



If, for some reason, you want to watch the GIF made from every data point (~ 15 MB), here you go.

You probably want to collect data rather than screen captures, but I made this to show that you it's certainly possible and it's already useful even in this sort of dreadful setup.

For instance, we can see that as the battery drains more (and therefore the DC-DC converters V_input gets closer to its V_output, which was about 7 volts or so), its noise increases (or certainly changes shape).

« Last Edit: October 12, 2017, 06:23:07 PM by technogeeky »
 

Online bd139

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Re: Rigol DS1054Z and slow processes
« Reply #3 on: October 12, 2017, 06:29:11 PM »
The DS1054Z doesn't have great voltage resolution so this probably isn't the best tool for the job.

I keep a Uni-T UT61E lying around for data logging. I've recently bought a GW Instek GDM-8341 for logging tasks but to be honest I haven't used it for that yet.
 

Online Fungus

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Re: Rigol DS1054Z and slow processes
« Reply #4 on: October 12, 2017, 07:00:56 PM »
The DS1054Z doesn't have great voltage resolution so this probably isn't the best tool for the job.

Nor do most 'scopes in this price range. They all use 8-bit ADCs.

As noted by everybody else, oscilloscopes aren't really the right tool for this job. They're designed for fast signals.

FWIW: The longest you can record with a DS1054Z is a couple of minutes.


 

Online Dubbie

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Re: Rigol DS1054Z and slow processes
« Reply #5 on: October 12, 2017, 07:32:01 PM »
Despite not being very precise technogeeky, that’s a cool little visual. I like how you showed the noise growing as the vbatt dropped.
 

Offline technogeeky

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Re: Rigol DS1054Z and slow processes
« Reply #6 on: October 12, 2017, 07:37:17 PM »
Despite not being very precise technogeeky, that’s a cool little visual. I like how you showed the noise growing as the vbatt dropped.

Thanks!

Yeah, when I set up the experiment I was telling myself: it's going to look really silly to just show an oscilloscope animation with a straight line moving, so what can I add to make it at least make a little sense as an experimental setup. I knew these units put some noise back onto their input so it was just the first thing that came to mind.

Cheers!

 

Offline oldway

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Re: Rigol DS1054Z and slow processes
« Reply #7 on: October 12, 2017, 07:50:52 PM »
Remember that to increase resolution and accuracy, you can use the differential method.

For example, to plot the discharge curve down to 10V from a 12V battery, you can measure the voltage difference between the battery voltage and a stable and accurate 10V reference.
 

Offline MrW0lf

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Re: Rigol DS1054Z and slow processes
« Reply #8 on: October 12, 2017, 08:07:05 PM »
Nor do most 'scopes in this price range. They all use 8-bit ADCs.
As noted by everybody else, oscilloscopes aren't really the right tool for this job. They're designed for fast signals.

8bit is not such a big issue when can average and do etc math trickery. I like math trickery. Yesterday measured phase of two 100MHz signals with 1MSa/s RTS :popcorn:
As for slow signals - here is current clamp warmup drift characterized over ~30min:

« Last Edit: October 12, 2017, 08:09:11 PM by MrW0lf »
 

Offline jkprg

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Re: Rigol DS1054Z and slow processes
« Reply #9 on: October 14, 2017, 02:46:31 AM »
Wow. Excellent. Thank you guys for all the answers.
 

Offline metrologist

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Re: Rigol DS1054Z and slow processes
« Reply #10 on: October 14, 2017, 03:32:39 AM »
I think if you use segmented record, you can capture on the scope periodically over a very long duration. The manuals says something like a sweep every 10 seconds up to 60k frames, which would be 166 hours. I seem to remember is being around 16 hours, but probably depends on some other settings...
 


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