A construction of a light scattering spectrometer and details of sample preparation suitable for a measurement of light scattering spectra are described. Usefulness of membrane filters is emphasized. Measurements of Landau-Placzek ratios are shown to be very useful for the confirmation of optical purity of a liquid sample. Experimental problems of intensity measurements of light scattering spectra are discussed. Brillouin intensities, Rayleigh intensities, Landau-Placzek ratios, and sound velocities are observed for various pure liquids. For the binary mixture of carbon disulfide and chloroform, concentration fluctuations are obtained by measuring concentration dependence of Rayleigh intensities.
Low pass filter having cut-off frequency under 1.6 Hz has been used to reduce statistical fluctuations in X-ray analysis. Smoothing low intensity X-ray diffraction signal is successful without changing the position and the profile of the original peak. The merits of using low pass filter, such as obtaining high resolution, detection of weak peak and accurate measurement of weak and broadened reflection, are also mentioned.