VATECH EzRay Air Manual Del Usuario página 38

3. Operation
To ensure proper alignment between the imaging sensor and the X-ray beam, it is
recommended to use a PID (Position Indicating Device) as shown in the following
figure.
PID
When using the PID, the exit pattern of the X-ray device should be aligned
perpendicular to the target receptor as shown in the following figure.
Once the PID is properly aligned, instruct the patient not to move.
28 EzRay Air (Model: VEX-P300) User Manual