A system is disclosed for measuring properties of samples associated with the distribution of hydrocarbons in the sample. The system includes a low resolution laser Raman spectrometer coupled to photodetectors that integrate the intensity of the scattered Raman radiation. The system further includes microprocessor means that separate the Raman spectrum into two spectral ranges, calculates a ratio of the integrated intensities corresponding to these ranges and interpolates that ratio with a correlating function to obtain the measurement of the property of interest.