#### Calculation of possible storage time

When a certified value $\mu_c$ and corresponding uncertainty $U_{abs}$ (`cert_val` and `U_abs`) are available 
for an analyte in **Tab.C3** of the certification module of *eCerto*, these can be used together with $\mathit{CI}_{upper}$ 
from **Tab.S2** to calculate the storage time $S_{Month}$ for each evaluated temperature level using:

$$S_{\mathit{Month}}(T) = \frac{ \log( \frac{\mu_c - U_{abs}}{\mu_c})}{e^{\mathit{CI}_{upper}(T)} }$$

***Note!***
It is recommended to use $\mu_c$ and $U_{abs}$ for these calculations. However, the user can alternatively use 
mean and 2 x standard deviation from the stability data of the reference temperature as an approximation by selecting 
the respective radio-button. Also, a direct input of the coefficient used in the above equation 
$\log(\frac{\mu_c - U_{abs}}{\mu_c})$ is possible.
