A method of reducing the frequency of taking background spectra when using one of FTIR spectroscopy or FTIR-ATR spectroscopy techniques, said method comprising the steps of: determining if there is a pre-existing background spectrum available; acquiring one or more scans of a sample of interest; determining one of acceptability of the pre-existing background spectrum or of a modified pre-existing background spectrum either (a) before acquiring the one or more scans of the sample or (b) after acquiring the one or more scans of the sample; wherein said determining the acceptability of the pre-existing background spectrum or of the modified pre-existing background spectrum includes: acquiring one present background scan; characterised by comparing the present background scan and the pre-existing background spectrum to determine if there are any non-conformities there between; if one or more non-conformities are found between the present background scan and the pre-existing background spectrum , determining if the one or more non-conformities are resolvable or not; if the one or more non-conformities are resolvable; resolving each non-conformity by adjusting the pre-existing background spectrum in a manner determined to resolve the one or more non-conformities, using one or more of: an algorithm, a calculation, calibration information, a graphical relationship, data; and if the one or more non-conformities are not resolvable, then acquiring a new reference spectrum. determining if there is a pre-existing background spectrum available; acquiring one or more scans of a sample of interest; determining one of acceptability of the pre-existing background spectrum or of a modified pre-existing background spectrum either (a) before acquiring the one or more scans of the sample or (b) after acquiring the one or more scans of the sample; wherein said determining the acceptability of the pre-existing background spectrum or of the modified pre-existing background spectrum includes: acquiring one present background scan; characterised by comparing the present background scan and the pre-existing background spectrum to determine if there are any non-conformities there between; if one or more non-conformities are found between the present background scan and the pre-existing background spectrum , determining if the one or more non-conformities are resolvable or not; if the one or more non-conformities are resolvable; resolving each non-conformity by adjusting the pre-existing background spectrum in a manner determined to resolve the one or more non-conformities, using one or more of: an algorithm, a calculation, calibration information, a graphical relationship, data; and if the one or more non-conformities are not resolvable, then acquiring a new reference spectrum. acquiring one present background scan; characterised by comparing the present background scan and the pre-existing background spectrum to determine if there are any non-conformities there between; if one or more non-conformities are found between the present background scan and the pre-existing background spectrum , determining if the one or more non-conformities are resolvable or not; if the one or more non-conformities are resolvable; resolving each non-conformity by adjusting the pre-existing background spectrum in a manner determined to resolve the one or more non-conformities, using one or more of: an algorithm, a calculation, calibration information, a graphical relationship, data; and if the one or more non-conformities are not resolvable, then acquiring a new reference spectrum. <EOS>