Average Ratios (Ravg) of Response of Commercial Activity Calibrators to 18F and 68Ge in Mock Syringe Geometry at Appropriate 68Ge Dial Setting (Table 2) for Each Specific Calibrator
| Chamber | Ravg |
| CRC-12 | 1.015(8) |
| CRC-15R | 1.022(7) |
| CRC-25PET | 1.016(10) |
| CRC-35R | 1.010(6) |
| CRC-1.8 atm | 1.018(6) |
| AL-500 | 0.997(21) |
Ratios were obtained by dividing activity readout from chamber for each 18F-FDG source by NIST-calibrated activity for that source. Uncertainties on response ratios were calculated from SD on average measured ratio from 3 sources and average uncertainties on 68Ge and 18F activities in mock syringes.