Statistical conversion factor between measurements of EMI in different test facilities

Measuring electromagnetic disturbance field strength often refers to open area test site measurements. Due to the largeness of open area test sites and their requirements to the environment they can rarely be found in middle-Europe. Additionally the need of the heightscan of the receiving antenna enlarges the necessary time of a measurement, so that alternative test sites were developed to avoid these disadvantages. Using test sites for emission testing that are in use for immunity tests seems to be a way to avoid the disadvantages of the open area test sites. In this context the correlation between measurements on different test sites becomes important. In this paper, a statistical approach including a generally valid model for all kinds of equipment under test is described. It is applied to the conversion of perfect fully anechoic chamber to perfect open area test site measurements.