How often do references need to be measured when using a near infrared diode array spectrometer

Abstract

The stability of a diode array spectrometer in the near infrared region has been investigated in two experiments where the frequency of passing of dark and white references, which need manual intervention, was varied. In the first experiment an initial pair of references was used to standardise spectra taken over the next four days. In the second, references were taken at hourly intervals over a period of ten hours. The conclusion is that in a reasonably well controlled environment the spectrometer is stable over long periods, and the passing of hourly references conveys no advantage. An important implication is that this spectrometer may be used in on-line applications without the need to construct an automatic mechanism to measure references.