Statistical analysis of experimental data obtained from the optical pendulum

The experimental measurement devices, in this case optical pendulum is tested to determine the system parameters and also to evidence the system performance. Experimental data obtained from measurement system is affected by errors. It is important to take steps to minimize the errors and also to understand them in order to be better understand the result of the experiment. The statistic analyze of experimental data is used to identify the errors and to reject them. The errors are caused by human inaccuracies like a wrong experimental setup or by the measurement systems errors. A used method is Chauvenet´s criterion. This can identify the bad data or wild point and discard them from experimental series. Applying a normal statistical test certifies the normal distribution of data and also estimates the confidence level of variance of the experimental data. The transfer function of optical pendulum is a polynomial parametric equation with parameters obtained from experimental data. Erroneous parameters affect the performance of the measurement device. Experimental data processing was done in MATLAB. The measurement system accuracy is by ±55 μm on OX and ±150 μm on OY direction.