This work is devoted to an experimental study of the possibility of introducing a new non-linearity calibration method for the high precision event timer based on obtaining the incomplete calibration table and filling it with various data interpolation methods. This would eliminate the issues of the currently used calibration method, which requires highly stable low jitter generator. Instability of the oscillator can cause calibration failure, leading to the need of sending the device for repair, which causes additional expenses for both client and manufacturer. The structure of picosecond precise event timer is discussed in the paper. The comparison analysis of various time interval interpolation methods, such as Vernier interpolation tapped delay interpolation, analogue memory method is performed. For analysis the measurements data of event timer non-linearity of the interpolator has been used the accuracy, robustness against errors, and computation speed are evaluated for all observed interpolation methods. Based on the experimental results of interpolation study, a novel non-linearity calibration method is proposed.