The WG2 of CISPR/SC-I is discussing a reference test method for measurement of conducted disturbance voltage at mains port. A statistical approach seems to provide reasonable evaluation results to determine that multiple test methods are alternative methods. In the study reported here, we obtained data from measurements of the conducted disturbance voltage at mains port, taken with two different test arrangements. The data recently gathered by VLAC (Voluntary EMC Laboratory Accreditation Center, Inc.) in two proficiency testing (PT) programs; we processed the data statistically and evaluated the results. From the results, we were able to conclude that measurements taken with two test arrangements could be used as alternative test methods.