The Transfer Function is measured on the Star of the month. 
It should be measured each VLTI SM night at the beginning of the night.
The TF is measured in 5 bins. Each bin is averaged over 5 channels.
bin1: 8.64 microns. 
bin2: 9 microns. 
bin3: 10.46 microns.
bin4: 11.79 microns.
bin5: 12.8 microns.

The TF is displayed here for bins 2 to 5.