.. index:: 
   single: Parameters; 1D Field Centre Infl

1D Field Centre Infl
====================

The field centre (*FC*) is defined as the distance in cm from the centre of the detector to the centre of the field and is calculated as the half the difference between the distance from the profile centre to the :ref:`right<1D Right Infl>` and :ref:`left<1D Left Infl>` inflection points:

.. math:: FC = \cfrac {d(RE) + d(LE)} {2}

Where *d(RE)* and *d(LE)* are the linear distances from the profile centre to the right and left inflection points respectively.

**Protocol invocation name**: 1D Field Centre Infl