The electromagnetic (EM) clamp is a high efficiency broadband clamp-on injection device developed to test the immunity of electronic equipment when the standard IEC 1000-4-6 CDN using the direct capacitive coupling technique is not possible nor appropriate. The EM Clamp is often used to test unshielded multiple conductor cables. The figure below shows a typical test setup using the EM Clamp and a ferrite tube decoupling network.