Abstract: An additive manufacturing system may include an additive manufacturing machine and a control system. The additive manufacturing machine may include one or more irradiation devices respectively including a beam source configured to emit an energy beam, an optical assembly that has one or more optical elements configured to focus the energy beam emitted by the beam source, a beam source sensor configured to determine a beam source sensor value from a source measurement beam representative of the energy beam prior to the energy beam passing through one or more optical elements of the optical assembly, and an optics sensor configured to determine an optics sensor value from an optics measurement beam representative of the energy beam downstream from the one or more optical elements of the optical assembly.