What are Fixed Error / Non Adjustable Errors Of Sextant.

They are also called as non-adjustable errors which can’t remove.

  • Centring Error:-  When Index’s Arm centre of rotation not at the centre of the arc.
  • Graduation Error:-  When graduation arc is not accurate.
  • Shade Error:-   When the faces of each shade are not ground to exactly parallel.
  • Prismatic Error:-  When the faces of each mirror are not ground to exactly parallel