A factor that corrects for the compressibility of the @C00863@. The values of the measured quantities obtained after multiplication by the factor $$j$$ are independent of the pressure drop in the column. If $$p_{\text{i}}$$, $$p_{\text{o}}$$ are respectively the pressures of the @C00863@ at the inlet and outlet of the column, then $$j$$ is given by: $j=\frac{3\ [(\frac{p_{\text{i}}}{p_{\text{o}}})^{2}- 1]}{2\ [(\frac{p_{\text{i}}}{p_{\text{o}}})^{3}- 1]}$