percent voids

percentage void

The percentage of superficial area which is lost by holes, perforations, or cores.
References in periodicals archive ?
6 percent asphalt content, 4 percent voids, and stabilities over 3000 lb.
The pharmaceutical delivery system being sampled and tested is composed of micron-sized, hollow "wiffle ball" like spheres that have a large surface area and up to 70 percent voids.