Beam Alignment Tools
Model 7801, Isocentric Beam Checker I
The precision Isocentric Beam Checker I consists of a screen holder and a removable screen with tungsten markers that precisely define the corners, edges and center of the screen's 2 x 2cm, 5 x 5cm and 10 x 10cm fields. The screen holder has a bubble level, three thumbwheel-adjustable legs and a knob that rotates the screen ±360° in 15° increments. By placing and leveling the Isocentric Beam Checker I at the assumed isocenter, one can easily check the accuracy of the collimator field size indicators as well as the isocenter rotational stability, backpointer alignment and patient positioning lights. The screen can then be removed and placed on a sheet of "pre-packed" film for radiation and light field congruence testing.
Model 710-720, Tungsten Rotating Alignment Pattern
The Tungsten Rotating Alignment Pattern checks radiation and light field congruence and size, laser alignment and gantry, collimator and table isocentricity. Embedded 1mm diameter tungsten rods and tungsten-filled lines are used to give a sharper image on films. Square line patterns are visible for 10 x 10cm and 20 x 20cm fields.