The optimization of data in analytical chemistry is a problem encountered in many research laboratories. Several authors have worked out theoretical and experimental methods for enhancement and for measurement of signal/noise ratio (S/N). Recently, Wehrly et al. described an electronic circuit to increase the S/N by digitally averaging data. The purpose of the present paper is to explain how one can achieve the same result in a much simpler and less expensive way by using a low-pass filter. Discussions will be limited to the instruments whose data are obtained in the form of recorded spectra from dc signals.
Alain Tessier, René Le Sage, and Roger M. Leblanc, "Simple Low-pass Filter to Reduce Noise in Direct Current Signals: Application to the Fluorescence of Chlorophyll a at Low Concentration," Appl. Spectrosc. 34, 226-227 (1980)