STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[Omnibus]

@teslaalset,

Very good analysis. Now, the main question I have is, is the current and voltage measured using the current probe and this 1X voltage probe (in the arrangement excluding the current through probe which is the arrangement used in these studies) the true current passing through the RC and voltage applied to the RC? If this were an electrochemical system (I'm thinking in the usual DC case; in the AC too) and we're measuring the voltage between two electrodes with such 1X voltage probe I would reject results which show current going through the probe. Such voltage has to be measured with current passing through probe practically zero because otherwise the electrodes will be polarized and will be of lower value than the open circuit voltage we need to know. In this case, however, there's no danger of such polarization as far as the system with the components we're measuring is concerned. Thus, is 1X voltage probe good enough in this case, despite the current flowing through it, if when carrying out the measurements we exclude that current (as we're actually doing)? Aslo, why are the results with the 10X voltage probe so different? Which one of the probes (1X or 10X) gives more accurate results?

Also, notice, the curves taken you've analyzed above are the average of 16 samples, not just one, despite the time being just one period. Shouldn't this be enough when you say that more than one period is needed?

[teslaalset]

@Omnibus,
I agree with you that the measurement setup you already used is best.
Although I do not fully understand why there is a non-reproducibility in the case of measuring voltage 'behind' the current probe, but let's leave that for now.
I believe you do measure all current in the actual RC circuit.
I am still studying the differences between the 1x and 10x probes.
The only thing I can think of is a difference in impedance of the probes.
Your signal generator should have sufficient low output impedance not to be influenced by these probes.
The only thing I can think of is the BNC termination impedance of the DSO versus the impedance of the probes (The input of the DSO does also have a typical impedance if set to high impedance termination).

Good to know you used data that was already the average of 16 single triggered curves.
As you can see from my analysis the reproducibility is good if you apply the voltage probe before the current probe.

[Omnibus]

Do you think I should average even more samples. The limit is 512? The effect is obviously due to subtleties in the behavior of I and V and I think we should go out of our way to understand what these are and whether or not the effect is due to experimental errors. That has to be shown beyond a doubt. So, what we're looking for are some critical experiments to definitively exclude experimental errors.

[teslaalset]

Do you think I should average even more samples. The limit is 512? The effect is obviously due to subtleties in the behavior of I and V and I think we should go out of our way to understand what these are and whether or not the effect is due to experimental errors. That has to be shown beyond a doubt. So, what we're looking for are some critical experiments to definitively exclude experimental errors.

Would be good to at least compare two measurements: one with no, or small, average and one with max (512) average.

[Omnibus]

These are data based on averaging 512 samples.