This SOP brings together in one place a description of the components of the Gafchromic? dosimetry system for Gamma Radiation, the procedure for its characterization?and its application to process validation and process control, together with references to the relevant standards. It provides a readily available source of information that can be accessed by both research workers and production facility managers. The SOP is published in two languages (English and Spanish). The Excel workbook for calculating Gafchromic? dosimetry is embedded in the SOP. Please download the SOP and open with Adobe Acrobat.