Graham joined the Radiation Dosimetry Group in 1985, working initially with the therapy level absorbed dose primary standard and helping to establish the world's first calibration service for secondary standards in this area. He then joined the sub-group responsible for environmental level, protection level (gamma and beta), LDR brachytherapy and ophthalmic applicator calibration services and the associated primary standards. During this time he developed measurement control software for the various radiation facilities at NPL used to automate the calibration of protection and therapy level secondary standards. In 2003 he became responsible for the therapy level electron secondary standard calibration service, overseeing the transfer of the service in 2008 from the research linac to the clinical linac.
Graham Bass is involved with various dosimetry calibration services, mainly therapy level absorbed dose using the clinical linear accelerator (linac) at NPL. He is also involved with off-site work, performing audits and beam data acquisition on behalf of hospital radiotherapy centres. Graham is performing many measurements on behalf of the linac manufacturer Elekta both at NPL and in the factory to establish performance compliance to IEC standards.