this pdf cpem-2016-keysight.pdf was mentioned in another thread about noise analysis

of interest is my incomplete understanding about the use of allan variance in finding a certain range of sampling which gives the best SNR

at some point in the 3458A plot, the SNR seem to get smaller

eg : for 10v, the best sampling is 10-20 samples? eye popping 150dB SNR

(150 SNR ~ 26 bits. 26bits @ 10v = 0.15uV per step. the best set of data I have is 0.6uV/24bits for similar range but needs 100x more averaging)

on most plots here in this thread contributed by users, it does not seem like 100NPLC is more noisy on 3458A than 10 NPLC

maybe theirs (on paper) is a different way of measuring?

on K2015, my previous messy data seem to suggest the best capture block is around 8NPLC. weird? but looking into the K2015 pdf, it also seem to suggest similar. with that, back then i then started to play in blocks of 2/4/8 binary increment NPLC blocks with interesting results.

in the other thread about the maths use, I used to think about the use of kurtosis. but after seeing allanvariance, i am imagining some kind of algorithm where there is a real time allanvariance calculation which adjusts NPLC as time progresses to get the most optimum sampling over time. or maybe the user specify a SNR and the software auto determines averaging and NPLC rate for fastest capture possible.

currently all of our captures are fixed NPLC.averaging, but noise and ambient intrusions are variables.

i found 2-3 xls online which has simple allan variance calculations. i tried to do something similar for noise but i could not get the allan variance to work. im sure my math is wrong somewhere

lets hope keysight doesnt do this first before one of us does and names it "true-nplc"