Analysis and evaluation of uncertainty for conducted and radiated emissions tests

• Main Author: Abdurrahim, Mohamed Emhemed
• Format: Dissertation
• Language: English; English; English
• Published: 2013
• Subjects: TK Electrical engineering. Electronics Nuclear engineering; TK5101-6720 Telecommunication. Including telegraphy, telephone, radio, radar, television
• Online Access: http://eprints.uthm.edu.my/1963/

Whenever an EMC measurement is made, there are numerous uncertainties in different parts of the measurement system and even in the EMC performance of the equipment under test (EUT) which is being measured. It is important to be able to estimate the overall uncertainty, in particular, the test setup and measurement equipment uncertainty. However, making repetitive measurements can reduce the measurement uncertainty, but often economics of time do not permit that. Therefore, a practical process, which is used to evaluate uncertainty in EMC measurement a, according to the principle of uncertainty and conditions in EMC measurement is presented. In this study, an efficient analysis of uncertainty for both radiated and conducted emissions tests is performed. The uncertainty of each contributor had been calculated and evaluating the reported expanded uncertainty of measurement is stated as the standard uncertainty of measurement. This standard uncertainty is multiplied by the coverage factor k=2, which for a normal distribution corresponds to a coverage probability of approximately 95%. The result of calculating the uncertainty for both conducted and radiated emission tests showed that the overall uncertainty of the system is high and it must be lowered by reducing the expanded uncertainty for the dominant contributors for both tests. In addition, the result of applying the concept of CISPR uncertainty for both conducted and radiated emission tests showed that non-compliance is deemed to occur for both EUT of both tests. This is due to the result that the measured disturbances increased by ( ), above the disturbance limit.