Which device is used to determine body density by measuring air displacement?

Which device is used to determine body density by measuring air displacement?

• A. DEXA
• B. Bod pod machine
• C. MRI
• D. Ultrasound

Answer: (B)

Determining body density requires accurately measuring body volume. The Bod Pod uses air displacement to do just that. Inside a sealed chamber, the person sits still while the system measures how much air is displaced by their body. Separate from this, body mass is measured with a scale. Body density is then calculated as mass divided by the measured volume. From that density, fat and lean tissue estimates can be derived using established equations. DEXA estimates bone mineral content and soft tissue by X-ray attenuation, not by measuring air volume. MRI images tissues using magnetic fields and does not determine volume via air displacement. Ultrasound uses sound waves to assess tissue properties, not air displacement.

Determining body density requires accurately measuring body volume. The Bod Pod uses air displacement to do just that. Inside a sealed chamber, the person sits still while the system measures how much air is displaced by their body. Separate from this, body mass is measured with a scale. Body density is then calculated as mass divided by the measured volume. From that density, fat and lean tissue estimates can be derived using established equations.

DEXA estimates bone mineral content and soft tissue by X-ray attenuation, not by measuring air volume. MRI images tissues using magnetic fields and does not determine volume via air displacement. Ultrasound uses sound waves to assess tissue properties, not air displacement.