How does a perometer work ?
The perometer uses harmless infrared light to scan an accurate image of the limb. Infrared light transmitters located on two sides of the perometer frame project light towards photosensors on the opposing two sides. When the limb is placed inside the perometer frame and the light transmitters are activated, the limb effectively "blocks" the transmission of light from one side of the frame to the other, creating an electronic image or ellipse. As the frame is moved along the limb, a series of images are records every 1/2 cm., creating a highly accurate measurement of the limb size and volume.
