However, it must be emphasized that since there are infinitely many combinations of α and I0 which yield the same value of 𝑅 𝑐𝑡 0 , it is fundamentally impossible to directly measure α or I0 within the linear region of the kinetics. Measurements of α and I0 must, therefore, be conducted within the non-linear region of the kinetics (i.e., at high current densities).