Tungsten welding electrodes as absorbers come in good quality as mass production items. To use pins of defined length and insert them in a precisely machined RW3 plate is quite logical in order to simulate cross hairs and central beam marker. Another mass production items are tungsten carbide balls, as used in heavy duty ball bearings. The density is close to pure tungsten, and so the 4mm-balls are perfect for marking corners of different field sizes. 5, 10 and 15 cm.
The insert is easy to install inside the smartQA, and with the dimensions 16 x 16 cm it fits as well inside the Euromechanics Easy Cube.
The Insert_EPID-IMG includes a 20 step high resolution lead test as it is used in digital radiograpy. This allows fast quality checks on the Imaging beam.
As simple test is added to the insert: thin stripes of lead foil at the lower side of the insert are positioned close to the edges and form a square.
When the insert (inside the RT-smartQA or standalone) is perfectly flat on the couch top and in ISO center, the imager with horizontal beam will see only one thin horizontal line. In case of misalignment this line will be broad or even double as the front and rear lead stripes are seen as separate shadows.
Very simple.
