The Haefely EFT Verification Set (2499951) is for verifying the HV output with 50Ω and 1000Ω load. EFT/Burst generators are verified according to the standard IEC/EN 61000-4-4. Measurements of individual impulse parameters are performed using a termination to match the EFT/Burst generator output impedance (50Ω) and a voltage divider to reduce the impulse level so it can be displayed on commercial oscilloscopes. An oscilloscope with minimum 400MHz bandwith is required to properly display the EFT impulse.
The PAT attenuator series has been developed in response to the IEC 61000-4-4 amendment 2 (2001) and Edition 2 (2004) which extends the verification requirement to also include impulse meadurement using a 1kΩ load.