Air displacement plethysmography

ADP is based on the same principles as the gold standard method of hydrostatic weighing, but through a densitometric technique that uses air displacement rather than water immersion.

Air-displacement plethysmography offers several advantages over established reference methods, including a quick, comfortable, automated, noninvasive, and safe measurement process, and accommodates various subject types (e.g., children, obese, elderly, and disabled persons).

Because of inconveniences such as these and various technology difficulties, none of the early air-displacement plethysmographs were ever developed for common, everyday use.

Boyle's law states that at a constant temperature, volume (V) and pressure (P) are inversely related.

[1] Air displacement plethysmographs have been validated against main body composition assessment techniques: