Ensuring a good spectrum will increase the chances of a good match and identification for unknowns. The best spectra will be obtained by following the guidelines below:
Clean the diamond by rinsing with methanol or rubbing alcohol. Wipe gently to remove excess rinsing liquid and allow the diamond to dry before continuing measurement.
Measure the background immediately before measuring the sample. View the background spectra. It should be flat with no peaks present, and with minimal "noise". If the background contains any of these, then re-run the background. Do not let time elapse between background and sample measurement.
Apply the sample. The baseline should be flat and smooth. The absorbance should be greater than 0.1. and all peaks should be positive.