Star Test Patterns
Focal spot size can be determined by observing the regions of blurring which occur when a star pattern is radiographed by an x-ray source of finite dimensions.
Radiation from different areas of the focal spot will cause a periodic blurring of the pattern due to penumbra effects.
Knowledge of the geometric factors and the distance from the center of the pattern to the region where blurring occurs will permit the calculation of the focal spot size.
Technical Specifications
- Type 9-0.25-07: 4 Sectors / 7° each
- Type 9-0.25-360: Full Star 360°
- Type 9-0.5-14: 4 Sectors / 14° each
- Type 9-0.5-360: Full Star 360°
- Type 9-1.0-28: 4 Sectors / 28° each
- Type 9-1.0-360: Full Star 360°
- Type 9-1.5-36: 4 Sectors / 36° each
- Type 9-1.5-360: Full Star 360°
- Type 9-2.0-44: 4 Sectors / 44° each
- Type 9-2.0-360: Full Star 360°