- if both heads are open (without foil : flag = 1) - average
- if both heads are closed ( foil or foil + grid : flag = 0[2] ) - average
- if one of the heads is open (flag = 1) - its value is taken
- if only one of the heads has flag < 3 and is closed (flag = 0/2) - its value is taken
While energy spectra plotting flag value is taken into account for correct Energy Table
