Standard Practice for Determination of Metal Purity Based on Elastic Constant Measurements Derived from Resonant Ultrasound Spectroscopy

Importancia y uso:

5.1 Since the beginning of human history, currency has existed in the form of metal coins and bullion. Thieves learned that shaving some precious metal provided a method to change its value. Substitution of common metals for precious metals of higher value was commonplace until weighing methods became so accurate, that it became easily detected. Alloys were also used as substitutes until inexpensive spectrometers became available which ended the counterfeiting practice. The rapid rise in the value of gold inspired the unscrupulous to find a new method. Tungsten was widely used for light bulb filaments until regulations changed that market. The great abundance of tungsten now available, coupled with the almost identical density of gold, presented a new opportunity.

5.2 RUS provides a method to create an unique electronic signature for each piece tested which is operator independent.

Subcomité:

E07.06

Volúmen:

03.04

Número ICS:

19.100 (Non-destructive testing)

Palabras clave:

elastic properties; nondestructive examination; nondestructive inspection; production variation; quality control; resonance inspection; resonances and vibration characteristics; resonant frequency; resonant mode; resonant ultrasound spectroscopy;