Ca’Foscari University – Venice

EM quasi static field compensation for a large TEM

The laboratory is located about only 450m from main railway to Venice. The highly sensitive 300 KV TEM has stringent requirement for both AC and Quasi static EM field. A complete and comprehensive EMI survey shown that the nearby railway distorts magnetic field in TEM room exceeding allowable level.

A room sized Helmholtz cage with 6 coils (each direction two parallel loops) has been created and installed. EMI compensation system of Stefan Mayer Instruments, MR-3 Fast with 2 fluxgate magnetometers has been used to cancel both AC and near to DC magnetic field effectively.

The complete installation of coils, connections, tuning and final testing have been conducted within 3 days. The final EMI survey measurements have shown significant improvement of environment. The room now is in compliance with TEM EMI requirements.