Definitions for z-axis geometric efficiency (g.eff.)

• IEC 60601- 2- 44 Ed. 1 1999: Original definition

  • “the full width at half maximum of the sensitivity profile expressed as percentage of the full width at half maximum of the dose profile.”

• IEC 60601- 2- 44 Ed. 2 Am.1 2003: New definition

  • “the integral of the dose profile along the z-direction, integrated over the range subtended by the detector elements used during acquisition, expressed as a percentage of the total integral of the dose profile in the z-direction”

• g.eff. to be displayed on scan console when less than 70%