Hallo,
I am interested in inherent noise in the most sensitive mV/div range.
Can someone please post a file with about 100 kSamples in the most sensitive range with a 50Ohm termination without input.
Nice if I get the data from different scopes
This gives me the possibility to calculate some values.
Best regards
egonotto
100k on the display width. (many scopes what have more memory do not map all to display width. Many oscilloscopes also do not calculate mesurements from full memory or undecimated data. This may make big difference.
Noise is random distribution. Peak value depends amount of data and here we go very easu to area where we do not compare scopes as apples to apples. We have seen this over years also here. Also what you see on the screen depends not only how oscilloscope decimate and/or map acquistion tata to screen buit also it depends how fast wfm/s it do (again, amount of data)
What I did in previous image from Siglent here. Noise RMS. How we get reliable noise RMS so that it have really noise itself. This is why I use Sdev measurement instead of RMS. Then, also, as can see it is calculated from quite lot of data as can see this statistics.
And you see memory length is 700pts.
But this image screen have stacked several axquisition. Amount of sample data is over 500000 samples in this image one trace. And all is mapped in this image. This is one reason why different scopes are bit difficult to directly compare.
But if we calculate RMSnoise it do not so much matter how fast scope is.
Here in this
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1290409/#msg1290409 thread first message is attached noise images and also 1M inputs but covered with RF shield cap for eliminate external noise.
Full bw and 20M BW, 500µV/div and 1mV/div.
Sorry they have also 700pts data length but, as told they have on the screen around 500000 samples every trace. (so much over 100k you want.)
Peak value rough loose estimate for random noise you can get when you calculate 6 * Sdev. (or if want be very tight then 8*Sdev)
with automatic mesurements Siglent use full acquisition length and resolution (but here it do not matter because one sweep length is 700 (roughly 20000 times/s)
I have also checked it calculate Sdev right.