Once a background is collected click around to see spectra from a few pixels. The expected FPA image should be similar each time. A single beam spectrum (light intensity as a function of wavenumber which is measured by the detector) should have a similar shape each time and the FPA image should be free of debris. If you notice any large spots, navigate to a clean background position and reacquire the background measurement. When in doubt, contact your beamline staff!