RadiMation forum

Hello all,

I am using RadiMation version 2025.1.6 with device driver system 2026.2.25.1644
I want to calibrate the G-TEM cell (Schaffner G-TEM 500) of our laboratory. I want to use the IEC 61000-4-20:2022 (Constant field method) to calculate the Uniform field area. I have not found documentation about this standard, so I have some questions:
1) how do RadiMation consider the distance between every calibration point that I choose in the point setup? Is there a way to insert the distances between the points? What if I choose a rectangular cell instead of a squared one for the point setup, or a cell less than 50 cm of side? Do I have to insert some data, i.e. antenna distance, in the 1 point calibration phase to help the program in the calculation?
2) how works the extended tolerance percentage?
3) What do the cross-polar probability percentage represent?
4) What is the impact of the TEM mode verification on the calibration?
5) what do the average calculation do if I set 4 times instead of 1 time?

If you have a complete documentation of the calibration and measurement according to IEC 61000-4-20:2022 I'd like to read it.
Thank you for the support.

Hello,

Please find the information below related to your questions mentioned in the previous post.
We will look further into updating our documentation related to the UFA calculation regarding the IEC 61000-4-20:2022 (Constant field method)

1)
You do not need to define the distances between calibration points in RadiMation.
The Uniform Field Area (UFA) calculation is based solely on the measured field strength values at each point.
Grid shape and spacing are not applicable to the calculation performed by the UFA calculation.

2)
The extended tolerance defines how RadiMation evaluates points that fall outside the normal tolerance band.
It allows a limited number of points to deviate slightly more than the standard tolerance without causing the entire calibration to fail.
This helps to prevent small, local variations in the field from unnecessarily invalidating the UFA.

3)
During calibration, the electrical field is regulated in one primary direction (X, Y or Z). In practice, a portion of this energy is also present in the perpendicular directions.

The cross-polar probability percentage represents the expected contribution of these perpendicular (cross-polarized) field components in the generated UFA.
It is used to account for non-ideal polarization conditions in the evaluation of the field.

4)
RadiMation reports the TEM mode verification as a validation check of the generated field.
This information helps the test engineer assess whether the field conditions meet the requirements of the standard.
It indicates whether the field behaves as expected (dominant single direction), and therefore whether the resulting UFA can be considered valid.

5)
If you set the calculation to 4 times instead of 1 time, the system recalculates the average after each removal of a calibration point.
Here’s the practical difference:

Calculate 1 Time:
The average field is calculated once using all calibration points. Based on that single average, the system identifies and removes the four points that deviate the most. The average itself does not change during this process.

Calculate 4 Times:
The process becomes iterative. After each calibration point is removed:
The average field is recalculated using the remaining points.
A new “worst” calibration point is determined.
This repeats until four points are removed.

What this means in practice:
With 4 times, each removal affects the next decision, making the process more adaptive and potentially more accurate. With 1 time, all removals are based on the original average, which is simpler but less responsive to changes in the dataset.

So, setting it to 4 times results in a dynamic recalculation process, which can lead to a different (often more refined) final result.


I hope to have informed you for now!

With kind regards,