## 5 Conclusions  
The objective of this study was to compare two methods for measuring electromagnetic disturbance emissions generated by light sources. The current EN 55015:2019-11 standard  
Figure 14: Recorded QP values using the new and traditional method against the allowable limits for the 18 W LED lamp D under test, where: L—number of analysed values, AV—calculated average value, Min, Max—minimum and maximum values, Q1, Me(Q2), Q3—first, second and third quartile, R—range, S—standard deviation.  
Figure 15: Summary of test results obtained using the new and traditional test methods for the tested LED lamps A \(\div\) D.  
allows two equivalent methods to measure the radiated disturbance emissions of LED lamps in the frequency range of 30 to 300 MHz. However, the SAC method requires a large investment to build a test stand. Measurements must be carried out in a semianechoic chamber. To reduce the cost of building a test stand, the CDNE method was introduced in the previous edition of EN 55015:2013. With certain restrictions, this technique can be used to measure electromagnetic disturbance, and the test result obtained should be equivalent to that obtained using the SAC method. In particular, there is a provision in the aforementioned standard that if the lighting device under test meets the requirements set out for one of these methods, the device under test is considered to comply with EN55015. However, can the CDNE method always be used equivalently and interchangeably with the first traditional SAC method? The results obtained make it possible to state that the SAC and CDNE methods are not equivalent test methods because they give different test results, leading to ambiguity in deciding whether a given LED lamp tested meets or fails to meet the requirements of the standard.  
In a situation where the result is inconclusive, the question arises as to whether or not the tested lamp meets the requirements of the standard and the basis that decides which method is superior. In such disputable cases, in the opinion of the authors, the SAC method should be used to solve the problem, which performs tests with the use of more advanced techniques and measurement tools (in this method, tests are performed in an anechoic chamber, the tested object is placed on a rotating measurement table, and the measurement antenna on a special mast scans the values of disturbances in the horizontal and vertical axis and changes its height in the range of 1 to 4 m). However, an unquestionable advantage of the CDNE method is that the duration of the test is considerably shorter compared to that of the SAC method. The abovementioned advantages of the CDNE method make it suitable for use in quality control departments for EMC testing on production lines in industrial plants. Of course, the previously obtained results for a given product in production must be correlated with the results obtained using the SAC method. In further studies, the authors intend to identify factors that, when eliminated, will enable both methods to be used equally.  
Writing--original draft preparation, conceptualization, methodology, W.S.; writing--review and editing, D.K.; resources, validation, formal analysis, investigation, data creation, visualization, W.S., D.K., K.K. ([PERSON]) and K.K. ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
This research paper was developed under the project financed by the Minister of Education and Science of the Republic of Poland within the \"Regional Initiative of Excellence\" program for years2019-2023. Project number 027/RID/2018/19, amount granted PLN 11,999,900. The work was developed by using equipment purchased in the programs EU: POPW.01.03.00-18-012/09-00; UDA-RPPK.01.03.00-18-003/10-00.  
The authors declare no conflict of interest. The funders had no role in the design of this study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.