Before revision: Coaxial cable is well suited for use as a guard , if electromagnetic shielding is also required then triaxial cable should be used as depending on the type of buffer circuit any noise on the guard may be amplified in the output.
After revision: Coaxial cable is well suited for use as a guard ; if electromagnetic shielding is also required then triaxial cable should be used as depending on the type of buffer circuit any noise on the guard may be amplified in the output.