X-act D in use
Here is the X-act D being used against a lightbox to measure density.
Who are we?
About Us
We are a precision instrumentation company, supplying our high precision
digital densitometer X-act D to clients around the world
Our History
Quantum Dynamics (UK) Ltd is a precision instrumentation company based in Eynsham, Oxfordshire with roots going back to 1990. We design and manufacture electronic measuring instruments for non-destructive testing and radiography applications.
X-act D
Our precision digital densitometer, X-act D, is supplied to major distributors in markets such as the UK, Europe and more. Renowned for its high accuracy and simplicity of use, the densitometer is a world class non-destructive testing tool.
Supporting Engineering
When you buy from Quantum Dynamics, you’re buying directly from the engineers who built it. Every X-Act D unit is assembled and tested in-house in the UK, ensuring the precision and reliability our customers depend on.
10,000
+
Units sold
10
+
Countries
30
+
Years in industry
What's new with quantum dynamics?
Latest News
As of 8th June 2026, Quantum Dynamics has embarked on a path to market and sell their established handheld densitometer directly themselves. We are the manufacturer of the world-famous Digit-X that has been marketed and sold exclusively by Xograph for more than 30 years, and many thousands have been sold. The development of the Digit-X was a collaboration between Quantum Dynamics and Xograph back in 1998, and at this time the densitometer was used in medical and NDT applications. Since then, medical X-rays have become largely digital, not using film at all, and the product has specialised in being optimised for NDT applications, plus some medical applications that still use wet-film radiography.
The original Digit-X supplied for many years had a major technical boost in 2024 when it was redesigned to be purely digital, using a microprocessor and advanced Digital Signal Processing (DSP) techniques. This was done partly to modernise the instrument and improve its performance, but also because some of the legacy parts were becoming increasingly difficult to source. This new product had some technical success, but Quantum Dynamics also faced some unexpected supply difficulties. In the first half of 2026, Xograph decided that the product was not a natural ally of their medical instrumentation and accessories, and so a very amicable parting was agreed upon.
Quantum Dynamics made some significant software enhancements to make the product even more attractive, and now offer it directly under the new name X-act D. It is expected that most sales will be through distributors, as QD is an electronics and instrumentation company, rather than a marketing outlet; however full technical support, warranties, calibration and service will be done directly by Quantum Dynamics at their premises in Oxfordshire.
With this new arrangement underway, we are actively seeking business partners with whom we can exploit the very significant market for X-ray densitography of wet-film X-rays. The biggest part of this market is Non Destructive Testing (NDT) but we also perceive markets in dentistry, veterinary, photography and other niches or areas of expertise. Also in countries which still use wet film for medical X-rays, the instrument is ideal for quantifying X-ray image density to assist patient diagnosis.