Table 4 The uncertainty components for measurements of the FWHM and penumbra
Uncertainty component | Type A (%) | Type B (%) |
|---|---|---|
Optical density measurement | 0.10 | 0.02 |
Intensity resolution | 0.002 | |
Uniformity of the radiochromic film | 0.50 | |
Temperature and relative humidity measurements | 0.056 | |
Alignment of the PMMA phantom with the PPS calibration center | 0.20 | |
Positioning of the radiochromic film inside the phantom | 0.16 | |
Calibration curve fitting | 1.33 | |
Measurements of FWHM and penumbra | 0.02 | 0.01 |
Standard relative combined uncertainty | 1.45 | |