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Quote from: alsetalokin4017 on July 24, 2016, 12:33:37 pmWould you at least concede that two channels connected to the exact same signal should report the same RMS value for that signal?Both CH1 and CH2 connected to the probe calibrator output:What happens when you swap the trigger to the other channel?
Would you at least concede that two channels connected to the exact same signal should report the same RMS value for that signal?Both CH1 and CH2 connected to the probe calibrator output:
Quote from: tautech on July 24, 2016, 12:42:23 pmQuote from: alsetalokin4017 on July 24, 2016, 12:33:37 pmWould you at least concede that two channels connected to the exact same signal should report the same RMS value for that signal?Both CH1 and CH2 connected to the probe calibrator output:What happens when you swap the trigger to the other channel?This.
To me, the pulses/pluses update is nearly meaningless. I know what they mean. I don't use an oscilloscope for a language lesson. I want measurements.So the phantom CH2-4 Vrms bug is the kind of thing that irks me. I don't have enough money or accurate enough secondary equipment to know if some values are wrong, or have high statistical (or in this case, systematic) error. I mean, I know that there shouldn't be a reading without a probe in, but once you get into the realm of plausibility, I will have to accept the results the scope gives me.I am hopeful that this community will make progress unpacking/decoding the firmware and we'll being to take more control over it ourselves.
Again, it's not THAT important but it is (to me) a sign that they are not taking things seriously, i can understand a spelling error, nobody's perfect, i can't understand not solving it because it is really so simple to fix.. and they are still not fixing or rather "fixing" other bugs and nuisances 'on the side'so, i can't trust them...
Quote from: JPortici on July 24, 2016, 09:53:58 pmAgain, it's not THAT important but it is (to me) a sign that they are not taking things seriously, i can understand a spelling error, nobody's perfect, i can't understand not solving it because it is really so simple to fix.. and they are still not fixing or rather "fixing" other bugs and nuisances 'on the side'so, i can't trust them...+1. This is the issue exactly, and is not brand-specific. It's a matter of being able to have a reasonable amount of trust in the equipment. The manufacturer's failure to address little things makes you wonder what more important problems are being overlooked or ignored.
Quote from: Fungus on July 24, 2016, 03:44:58 pmQuote from: tautech on July 24, 2016, 12:42:23 pmWhat happens when you swap the trigger to the other channel?This. This:
Quote from: tautech on July 24, 2016, 12:42:23 pmWhat happens when you swap the trigger to the other channel?This.
What happens when you swap the trigger to the other channel?
The periodic RMS seems more accurate. This makes sense (it will look for a complete wave so it's less dependent on horizontal scroll position).Anything else is interesting... but nitpicking. Oscilloscopes are for looking at the shapes of things, not precise voltage measurements. Between 8-bit DACs and background noise you're never going to achieve more than about 10% accuracy.
So almost 50% higher RMS reading on second channel on your own screenshot is nitpicking?
Quote from: wraper on July 25, 2016, 10:03:36 amSo almost 50% higher RMS reading on second channel on your own screenshot is nitpicking?It's not 50% when you get a reasonable number of pulses on screenIt's never 50% on the "Per.VRMS" reading.
Quote from: Fungus on July 25, 2016, 10:08:07 amQuote from: wraper on July 25, 2016, 10:03:36 amSo almost 50% higher RMS reading on second channel on your own screenshot is nitpicking?It's not 50% when you get a reasonable number of pulses on screenIt's never 50% on the "Per.VRMS" reading.Does it tell you how many pulses are reasonable enough so you can trust it?
Does it tell you how many pulses are reasonable enough so you can trust it?
Reminds me of EE101 lab. First year in undergrad the lab supervisor made sure we would never trust a scope (or any other T&M) ever again. Simply spoken - until you understand exactly what the scope does everything it shows is meaningless. Everything. (This was mid 80's so this was Tek and HP scope days - none of this Rigol stuff).
In this specific instance I would assume an easy way to know if your RMS reading has stabilized is to add more cycles (change Timebase). At some point the VRMS would stabilize.
Quote from: wraper on July 25, 2016, 10:10:12 amQuote from: Fungus on July 25, 2016, 10:08:07 amQuote from: wraper on July 25, 2016, 10:03:36 amSo almost 50% higher RMS reading on second channel on your own screenshot is nitpicking?It's not 50% when you get a reasonable number of pulses on screenIt's never 50% on the "Per.VRMS" reading.Does it tell you how many pulses are reasonable enough so you can trust it?Reminds me of EE101 lab. First year in undergrad the lab supervisor made sure we would never trust a scope (or any other T&M) ever again. Simply spoken - until you understand exactly what the scope does everything it shows is meaningless. Everything.
until you understand exactly what the scope does everything it shows is meaningless.