On-site EMC testing and interference prevention

Complex measurement systems being assembled on site have been found to suffer from electromagnetic interference although components of the systems passed the required electromagnetic compatibility (EMC) tests. We present an on-site test system that allows for the EMC evaluation of on-site assembled large measuring system installations in the frequency range from 27 MHz up to 5.8 GHz and propose a solution for interference prevention therein. E.g. weigh bridges for large vehicles and other measuring instruments being subject to legal metrology must not display readings influenced by radio frequency fields [1-3]. A multi-sensor system integrated into the electronics detects any unintentional RF signals coupled into the measuring device and prevents further processing of measured data which are likely being disturbed by RF energy coupled into the system.