There are two main types of X-ray tubes:

1. Open X-ray tube (open tube):
   • Characteristics:
     • Expensive upfront cost.
     • Requires regular maintenance.
     • Self-calibration capability.
     • Consumables include filaments and targets.
     • X-rays are transmitted through the target.
2. Conventional enclosed radiographic tube (closed tube):
   • Characteristics:
     • Lower initial cost compared to open tubes.
     • Maintenance-free.
     • Tube lifespan typically around 5000 hours, after which replacement is necessary.
     • Aging may lead to increased focus and image blurring.
     • Consumables include the tubes themselves.
     • X-rays emitted via refraction.

The primary parameters of an X-ray inspection machine for automotive applications include:

1. Magnification:
   • Geometric and optical magnification.
   • Digital enlargement via computer for detailed observation.
2. Manipulator:
   • Anti-collision design.
   • Higher precision with more shafts.
   • 360-degree plane rotation.
   • Sample holder.
3. Radiation Protection:
   • Compliance with international standards for radiation leakage (typically less than 1µSv/hr).

Key parameters for X-ray tubes in an X-ray machine include:

• Voltage in kV
• Tube current and tube power
• Target current and target power
• Relationship between tube power and target power
• Target current measurement
• Focus port size
• Spatial resolution
• Focal size vs geometric shading
• Feature resolution
• Detail detectability of the system

Image quality is influenced by several factors, including:

• Parameters of the X-ray tube such as spatial resolution, target current, detail detectability, and focus port size.
• The detector used.
• Geometric magnification.