S/N Validation

[Elmiko]

I'd like to validate my system's s/n calculation and thought that doing a manual calculation would be a good idea. It was always easy to estimate peak-to-peak noise on an integrator or strip chart. But, on a digital system, it's almost impossible to visually estimate the noise on any chosen baseline segment because there really is none. Any ideas as to how to confirm my system's (EZChrom Elite) calculated results?

Also, what's the most popular method: peak-to-peak, 6-sigma, or ASTM?

[unmgvar]

what is your current SOP for calcuating S/N?
my experience is that almost nobody has a fully detailed way of how they do S/N.
to the best of my remembrance (ezchrom 3.1.7) S/N is done using the full value of the noise and not noise/2.
also you can only use the noise calculated on the entire range of the chromatogram when using the S/N annotation and you cannot specify a given RT window or use the width of your peak as window reference.
the other possibility is to get the noise only and then using the advanced reporting options do a S/N calculation.

as to which method to use, if i remember well, ezchrom has Root to Mean Square, 6-sigma and ASTM. generally 6-sigma would give a result like peak to peak