Use of equations for the description of experimental dependence of the height equivalent to a theoretical plate on carrier gas velocity in capillary gas-liquid chromatography. 
Optimal equation for fitting the experimental data on the height equivalent to a theoretical plate (HETP) versus carrier gas velocity in GLC was determined.  The data obtained by authors and the literary data by other investigators were used for the comparative study of Van Deemter, Golay and the little known Golay-Guiochon equations.  The Golay-Guiochon equation takes into account instrumental contribution and other sources of additional band broadening.  Correlation coefficient R and Pirson's criterion chi2 were used as a criterion of the data correspondence to the equations.  The Golay-Guiochon equation is the best for fitting of the experimental data in 71% considered examples, 19% experimental data may be fitted very precisely by the Van Deemter equation, the Golay equation is preferable for 7% experimental data only.  Three percent experimental data may be fitted with the same precision by the Golay and the Van Deemter equations.  The results obtained are of theoretical and practical interest.  The Golay-Guiochon equation must be used more widely in analytical practice and physicochemical measurements.