Professional comparison

When two FTIR spectra look different, find out which differences actually matter.

Submit two spectra and the question you need answered — for example incoming versus qualified reference, failed versus known-good sample, before versus after treatment, or a suspected material versus reference. Receive a focused comparison and written conclusion tied to that question.

Two FTIR spectra overlaid for specialist comparison
Best forA clearly defined question involving exactly two spectra

Use it when a generic similarity score is not enough and the practical decision depends on understanding where the two spectra agree, where they differ and how meaningful those differences are.

Common situationsIncoming vs reference · failed vs good · before vs after

The service can support QC investigation, material verification, treatment comparison, ageing or failure review when the two samples and the comparison question are well defined.

Client valueA conclusion tied to the question, not a page of unexplained spectral differences

Receive the overlay, important regions and peak-level changes together with a written interpretation, confidence and limitations that can be shared internally or with a customer.

01 · Define the question

The comparison starts with what you need to decide

Two spectra can differ for many reasons. Tell us the relationship between the samples so the review focuses on the differences relevant to your problem.

Your comparison question

Describe whether this is a consistency check, reference comparison, failure investigation, treatment comparison or another two-sample question.

Sample context

Provide material, process, batch or treatment information that helps distinguish expected variation from an analytically important change.

Comparable spectra

Where possible, use spectra collected under comparable sampling and acquisition conditions; method differences can otherwise create apparent spectral changes.

02 · Deliverable

What you receive

A written assessment with the comparison evidence organized around the question you submitted.

Spectral overlay

The two spectra shown together with important regions of agreement and difference.

Peak and region differences

Relevant wavenumber shifts, intensity or shape changes, new or missing bands where the data supports those observations.

Written conclusion

A direct answer to the stated comparison question, with the supporting evidence, confidence and limitations explained.

03 · Scope

What two-spectrum comparison can and cannot establish

FTIR can provide strong evidence of spectral similarity and meaningful band differences, but two spectra alone do not prove that every component, concentration or cause is identical or uniquely determined. Orthogonal testing may be needed when the decision requires information outside the FTIR evidence.

Submit the comparison

Upload both spectra and tell us what decision they need to support

The clearer the relationship between the two samples and the question, the more focused the comparison can be.

FTIR evidence review for a two-spectrum comparison
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