In this article we review a shielded power cord produced by German factory .
This cable is shielded with metal plated Mylar foil, and covered with PVC。 The exterior appearance is the same of an unshielded power cord which is sold together with the PC or monitor, the cable is just a little thicker。
The cable is about 2 m long, it has the Schuko type plug, like most power cords of computer related devices, and it conforms to the CE norms.
We have measured the electric field in the low frequency range (10 Hz - 2 KHz) with the cable inserted in the wall socket at 220 V AC and the other side not connected, with the cable laying straight on the floor far from other objects. The measured electric field is the same as the background field of the floor with no cables laying, so the shield eliminates almost completely the electric field.
We have also measured the magnetic field in the same low frequency range, when the cable is connected to a medium size computer turned on, the magnetic field is about 20% lower than that of an unshielded cable, which is normal because the metal shield can't absorb the magnetic field。
The shielding effectiveness of this product is almost the same of our handcrafted shielded power cord, at least for the low frequency range 10 Hz - 2 KHz, which is the most important in this case。 The cable is of good quality and it is effective for reducing greatly the electric fields in offices with many power cords。