Lethality calculation for thermal processes with different heating and cooling rates

In many thermal processes, the time constants f_h and f_c for the heating and cooling periods differ. This can cause difficulties in calculating the process lethality. This paper presents a simple method for taking into account this change in the time constant. The author's formula method is tested against simulated data from finite-difference computations, both for f_h=f_c and for f_h≠f_c , and found to be at least as accurate as the best previous formula method.