11 APD Measurement
Measurement Description
Traditionally, EMI measurements have been performed by EMI receivers using defined RBW and detector
modes like quasi-peak, peak and average. However, the advances in digital technology created a need for
a measurement method to protect digital radio communication services. APD was introduced in
Amendment 1:2005 to CISPR 16–1–1:2003 as a new weighting method to accurately determine the
electromagnetic disturbance emitted by electrical appliances or equipment, which degrade the
performance of digital communication system.
The APD of disturbance is defined as the cumulative distribution of the “probability of time that the
amplitude of disturbance exceeds a specified level”.
Key Path
Meas
Initial S/W Revision A.13.00
EMI Receiver Mode Reference 895