Temperature range in Mobotix M73


Recently we bought a thermal camera, specifically the Mobotix M73, for academic purposes and we need to know the temperature range of the recorded videos and snapshots.
However, when we try to either add $(IMG.TRM.) or &(IMG.TRP.) in the Text Display, it shows an error message of unknown subnet.
In addtion, we select the Thermal Range->Enabled in the thermal sensor settings and still we have no display of the temperature range.
Is there any other way, to display the temperature range on screen on Celsius or any other setting we missed?

Thank you in advance for your co-operation