An alternative method for conducting immunity tests in the industrial environment

For studying the electromagnetic compatibility (EMC) of any device, measuring the devices' immunity is very important. At present, most of the standards relating to immunity are designed for laboratories, and the immunity tests are always conducted by using coupling-decoupling networks (CDN) in laboratories, in accordance with the standard EN61000-4-6. However, these methods are not always feasible because of some limitations. If the equipment under test (EUT) has large dimensions or high currents, as in the case of most of the industrial equipment, it is not possible to send it to the EMC laboratory or to use CDNs for testing. To overcome this problem, an alternative method is proposed for conducting immunity tests in the industrial environment. In this paper, the test methods for the laboratory and for the industrial environment, the former with CDNs and the latter with current probes, are described first. From these tests, correction factors (CF) are extracted, based on the analysis of the loop impedances in the laboratory and the injected loop currents in the industrial environment. Finally, a link is established between the laboratory and the industrial environment, and then, the equalization between the two is realized by using these correction factors.