\(\delta_{\text{raw}\left(\text{sample}\right)}=\frac{R_{\text{measured}(\text{sample})}}{R_{\text{measured}(\text{wg})}}-1\) Eq. 1
\(\delta_{\text{true}\left(\text{sample}\right)}=\delta_{\text{raw}\left(\text{sample}\right)}+\delta_{\text{true}\left(\text{wg}\right)}+\left(\delta_{\text{raw}\left(\text{sample}\right)}\times\delta_{\text{true}\left(\text{wg}\right)}\right)\) Eq. 2