Application Notes

Raising the Bar for Gold Bullion Testing

Gold bullion testing with Olympus XRF Analyzers

Evident portable X-ray fluorescence (XRF) analyzers provide users with accurate surface chemistry of bullion bars, while Evident ultrasonic flaw detectors provide a nondestructive, fast, and reliable method for helping ensure that gold bars have not been adulterated. Combined, these two technologies enable users to be confident in the purity and integrity of their bullion bars.

Analysis without the need for drilling or cutting

The rise in fraudulently adulterated gold bullion bars by inserting slugs of inexpensive metals (such as tungsten) is a concern for gold markets. These insertions are difficult, and often impossible, to identify visually, by measuring the weight, or using radiography technologies. Portable XRF analyzers provide accurate analysis of precious metals, but are limited to the surface of the metal that is being analyzed.

Ultrasonic flaw detectors can be used to ensure that a bullion bar is homogeneous and free of insertions. When combined with portable XRF results, users can be confident that the surface chemistry obtained by their Vanta XRF analyzer is representative of the chemistry throughout the entire bar.

Ultrasonic flaw detectors work by generating pulses of high-frequency sound waves in a material, which then reflect back to their source after they strike a boundary with a different material. This could be the bottom of the gold bar, an insertion within the gold bar (e.g. a tungsten metal insertion), or an internal void. Evident flaw detectors can be used to distinguish between waves reflecting from the bottom of the gold bar and waves reflecting from insertions or internal voids.

This test is set up by coupling the transducer to a known good bar and identifying the echo from the bottom surface. A flaw gate may be used to monitor the interval ahead of this back wall. Any echoes appearing within the region marked by the gate indicate that the sound beam is reflecting off a discontinuity, and the bar should be further inspected by other means.

Benefits of Vanta™ XRF Analyzers

When accuracy and confidence count, the Evident Vanta XRF instrument provides immediate, on-site elemental measurements for analyzing precious metals, including gold, platinum, silver, and rhodium. Features include:

Continuous operation at temperatures up to 50° C (122 °F).

IP55/IP54 rated to withstand dirt, dust, and rain.

Rugged and built to pass a 1.2 m (4 ft) drop test (MIL‑STD-810G) to help prevent breakages.

Connect to the Olympus Scientific Cloud™ to access and share data across multiple platforms from any location.

^*1 With optional fan.
^*2 Requires optional wireless dongle.

Vanta GX

Accurate, easy to use, and nondestructive, the Vanta GX precious metals analyzer provides an affordable way to know the purity and composition of gold and other precious metals.

Vanta Max and Core

The Vanta™ handheld XRF analyzer series provides rapid, accurate elemental analysis and alloy ID in two powerful models. The Vanta Max analyzer offers the series’ highest analytical capabilities for robust applications, including mining exploration, mineral analysis, soil testing, and environmental analysis. The Vanta Core analyzer is the standard choice for fast alloy ID. Comfortable to hold, easy to use, and durable, the analyzers maximize efficiency in the field and lab.

OmniScan SX

The single group, lightweight OmniScan SX flaw detector features an easy-to-read 8.4-inch (21.3 cm) touch screen and provides cost-effective solutions. The OmniScan SX comes in two models: the SX PA and SX UT. The SX PA is a 16:64PR unit, which, like the UT-only SX UT, is equipped with a conventional UT channel for P/E, P-C, or TOFD inspections.

EPOCH 650

The EPOCH 650 is a conventional ultrasonic flaw detector with excellent inspection performance and usability for a wide variety of applications. This intuitive, rugged instrument is a continuation of the popular EPOCH 600 flaw detector with additional capabilities.