Instead of the bulky machine needed to produce X-rays, all that is needed to produce effective gamma rays is a small pellet of radioactive material in a sealed titanium capsule.
The capsule is placed on one side of the object being screened, and some photographic film is placed on the other side.
Detectors placed opposite the sources register the breaking of the beam and hence the level of coal in the hopper.
Such level gauges are among the most common industrial uses of radioisotopes.
The attributes of naturally decaying atoms, known as radioisotopes, give rise to their multiple applications across many aspects of modern day life (see also information paper on The Many Uses of Nuclear Technology).
Radioisotopes are used by manufacturers as tracers to monitor fluid flow and filtration, detect leaks, and gauge engine wear and corrosion of process equipment.
X-ray sets can be used when electric power is available and the object to be scanned can be taken to the X-ray source and radiographed.These gauges are most useful where heat, pressure, or corrosive substances, such as molten glass or molten metal, make it impossible or difficult to use direct contact gauges.The ability to use radioisotopes to accurately measure thickness is widely used in the production of sheet materials, including metal, textiles, paper, plastics, and others.The process of gamma radiography, a type of non-destructive testing (NDT), is used to validate the integrity of poured concrete and welds on fluid vessels, pipelines, or critical structural elements.The unique characteristics of gamma radiography have resulted in the technique becoming a crucial tool throughout many industries.