Radioactive dating gold
The IAEA estimates that several hundred thousand such gauges are operating in industry worldwide.They measure the amount of radiation from a source which has been absorbed in materials.Radioisotopes have the supreme advantage that they can be taken to the site when an examination is required – and no power is needed.However, they cannot be simply turned off, and so must be properly shielded both when in use and at other times.Fixed gauges are typically used in production facilities – mines, mills, oil and gas platforms – as a means of controlling and monitoring quality from a production process.For example, in the North Sea, fixed nucleonic gauges are sometimes deployed to determine conditions within separator vessels and to monitor residual oil content within separated gas streams.Detectors placed opposite the sources register the breaking of the beam and hence the level of coal in the hopper.
Gauges containing radioactive (usually gamma) sources are in wide use in all industries where levels of gases, liquids, and solids must be checked.
Gamma radiography has found use outside of core industrial applications, with the technique successfully employed following the devastating earthquake in Nepal in April 2015.
NDT was used to test the integrity of critical buildings such as schools and hospitals, as well as historical attractions.
There, the radioactive source is remotely exposed and a radiographic image of the weld is produced on the film.
This film is later developed and examined for signs of flaws in the weld.