The phantom‘s special feature is an optional kV test object. With it, the generator output stability can be monitored on a regular basis without performing invasive or non-invasive kV measurements. As the kV test object consists of 2 different materials, 2 transition points can be defined for a specific radiation quality. The accuracy of the method is +/-2 kV for a pure visual evaluation. When measured with a luminance meter (digital) or a sensitometer (film/screen), the accuracy of the method will increase to +/- 0.5 kV.