[lespaul]

Hey guys,

Quick question I was using a Nicolet FTIR with OMNIC 8.2 software installed this week and I noticed when I first collected the background spectrum (in this case, water) it asked if it wanted the software to collect the background 'before' or 'after' the sample spectrum.

Does this make a difference?

In the end the water background was subtracted.

Real world logic tells me I should of selected 'after' (I chose 'before') - hope my data isnt worthless now.

[Stepan]

I was under impression that background scan assumes a blank scan without a cuvette (just air). Usually it is taken first before any measurements and often used by the instrument for automatic self-tuning and diagnostic.

[lespaul]

Thanks Stephan,

Well it looks like the data is okay, I guess it doesnt really matter if you select 'before' or 'after' when subtracting a background (ie. water, air, solvent, etc).

Im new to OMNIC