How is Ultrasound Testing Used to Authenticate Precious Metals?

Gold and silver have been cherished for centuries, captivating humankind with their allure and enduring value. As these precious metals continue to hold a significant place in the global economy, the need for accurate and non-destructive testing methods has become paramount.

Enter ultrasound technology, an important testing technique often used by many industries to detect cracks, fractures, and defects in objects. How is ultrasound used in gold and silver testing? Let’s find out in this article.

The Need For Reliable And Non-Destructive Testing Methods

In the world of precious metals, the need for reliable and non-destructive testing methods is of paramount importance for investors, collectors, and traders alike. After all, who would want to buy precious metals only to discover later that they purchased counterfeit coins or bars?

However, traditional destructive testing methods, such as the fire assay, can be effective but come at a high cost – the destruction of the very bullion bar or coin being tested. Such an outcome is obviously unacceptable for buyers of bullion bars and coins for investment purposes!

This raises the demand for alternative testing techniques that offer accurate results without compromising the physical integrity of precious metal items.

How Is Ultrasound Testing Used To Authenticate Precious Metals?

Ultrasound testing has become an invaluable tool for authenticating precious metals, providing a non-destructive and highly reliable method for verifying the purity and integrity of gold and silver items. In this process, high-frequency sound waves are directed into the metal, and their interactions with the material are analyzed to yield crucial information about its composition.

When it comes to silver and gold testing, an ultrasound machine is used to determine the thickness of the tested bullion bar or coin. This thickness measurement is then compared to the thickness of an authenticated sample to determine if the tested material is free from tampering.

What is the Speed of Sound Travelling Through Precious Metals?

Below is a table showing the celerity (speed of sound), density, and electrical conductivity of gold, silver, platinum, tungsten, and lead.

Metal Celerity Density Electrical Conductivity
(m/s) (g/cm³) (MS/m)

Gold 3240 19.32 44.2

Silver 3650 10.49 63

Platinum 2680 21.45 9.4

Tungsten 5170 19.25 18.4

Lead 1210 11.34 4.7

Note:

• Celerity is the speed of sound through the material, measured in meters per second (m/s).
• Density is the mass per unit volume, measured in grams per cubic centimeter (g/cm³).
• Electrical Conductivity is the ability of a material to conduct electricity, measured in MegaSiemens per meter (MS/m).

Steps to Test Precious Metals with Ultrasound

Gold and silver have been cherished for centuries, captivating humankind with their allure and enduring value. As these precious metals continue to hold a significant place in the global economy, the need for accurate and non-destructive testing methods has become paramount.

Enter ultrasound technology, an important testing technique often used by many industries to detect cracks, fractures, and defects in objects. How is ultrasound used in gold and silver testing? Let’s find out in this article.