CISPR 22 conducted common mode voltage measurements along a wire using a capacitive voltage probe

CISPR 22 (1997) defines the limits of conducted common mode emissions (disturbances) permitted from information technology equipment (ITE) over the frequency range of 150 kHz to 30 MHz. Of significant interest are conducted common mode emissions from telecommunications ports and cabling of the ITE that are used for the transmission of digital signals using unshielded twisted pair (UTP) cabling. This paper presents the results of conducted CM voltage emission measurements made with a capacitive voltage probe (CVP) on a balanced and unbalanced UTP.