The EM-2107A is a standard test fixture for evaluation of the electromagnetic shielding effectiveness of planar material. The fixture is an enlarged section of coaxial transmission line and complies fully with the requirements of ASTM test method D4935-1. The measured data relates to the shielding effectiveness due to a plane wave (far field EM wave) from which near field values for magnetic and electric fields may be inferred. The EM-2107A is provided with a reference standard test specimen, a dynamic range specimen. Dynamic range of greater than 80dB is achievable, although the cables and other test system components usually establishes the limiting factors.