Importance

Loading Importance Indicators...

Abstract

The present invention provides a nuclear radiation backscatter gauge and method by which an accurate determination of the density of a test material can be made, even though the test material may have surface irregularities or voids which would otherwise contribute significant error to the density measurement. The invention is based upon the use of a nuclear density gauge which is specially designed for measuring thin layers, and which is characterized by having a source and at least two separate detector systems mounted in geometrically differing relationships with respect to the source. Through the use of this type of gauge, in combination with a pad or block of known thickness and density, a measurement is made of the density of a top zone of a predetermined thickness which is greater than the thickness of the block and which thus encompasses not only the block but also an upper portion of the underlying material where the surface voids and irregularities exists. A density measurement is also made of the composite material, i.e. the block and the underlying material. The density of the composite material and the density of the top zone are then used to accurately determine the density of the material as it exists below the level of surface irregularities and voids.

Loading the Abstract Image...

First Claim