The regression approach with three models to describe the field electron emission signal is used. Each regression function has its own theoretical basis. Three-parameter models make it possible to take into account deviations of current-voltage characteristics in the Fowler–Nordheim coordinates from a straight line both in the region of high voltage values and in the region of low ones. The studied data samples were obtained as the result of the numerical experiment with the given signal parameters for a more visual comparison. A special noise model is considered, within which the use of traditional linearization by parameters seems fair. For regression residuals, attention is paid to checking for the distribution normality. Cross-estimation of the proposed models parameters is performed. Their statistical significance with the confidence level of 95% is checked. It is shown that for each set of experimental data it may be necessary to have its own model. As the measure of the response dependence on the factor in the work, the adjusted coefficient of determination is used.