Estimating realistic confidence intervals for the activation energy determined from thermoanalytical measurements

A statistical procedure is proposed for estimating realistic confidence intervals for the activation energy determined by using an advanced isoconversional method. Nine sets of five thermogravimetric measurements have been produced for the process of gassification of ammonium nitrate at five different heating rates. Independent estimates of the confidence intervals for the activation energy have been obtained from these data sets. Agreement with these independent estimates demonstrates that the proposed statistical procedure is capable of adequately estimating the actual uncertainty in the activation energy determined from a small number of measurements. The resulting averaged relative errors in the activation energy were found to be 26, 21, and 17% for three, four, and five heating rate estimates, respectively.