Software Automation for Electric Field Sensors Calibration

Electromagnetic field sensors play an important role in determining emissions and immunity of any kind of electronic device. In order to establish if the behaviour of the instrument under test is acceptable, the measurements performed with the sensors must be compared with the current limits and regulations. To ensure that the results obtained with different sensors in different testing environments are reliable and comparable, the sensors must be calibrated by laboratories that are accredited by a national resource. TESEO s.p.a. is one of the laboratories in Italy certified to calibrate electric field sensors, and it employs both a TEM and a GTEM cell, depending on the required frequency range. A precise procedure must be followed during the calibration, that requires time and accuracy. The aim of this thesis is to develop a software able to handle the calibration procedure of electric sensors in an automated way. The program was created with the software NI LabVIEW and it can handle both TEM and GTEM tests. It is able to communicate with all the instruments involved in the test chain and autonomously set the values of the input quantities to reach the desired behaviour of the system, and in the end it produces a report with all the measurements performed. The program was tested and applied to real calibration procedures. The results show that the software is able to perform the tests in an accurate way, optimizing significantly the amount of time needed and reducing the error factor introduced by human operators, thus obtaining an automated and reliable calibration procedure.