PD Measurement limitations

User limits of PD Measurement usage

Some points are important for a successful experiment: 

• Card must be in standard format with no transparent plastic edges (e.g. NIE)
• Follow the complete protocol: 
  - put the phone down on a stable environment
  - appropriate lighting conditions, no under & over exposure
  - hair tied back, face unobstructed

• Avoid movement to get a clear picture

• Sufficient and stable internet access

• Access to front camera