Nikon Metrology has announced the launch of an improved 225 kV, microfocus X-ray CT (computed tomography) system called the XT H 225 ST 2x. According to the company, the updated system has “a unique combination of five innovative features, taking usability and uptime to the next level.”
The metrology solutions provider says two of these features are exclusive to the XT H 225 ST 2x. The first, known as ‘Rotating.Target 2.0’, enables a 3 times smaller focal spot size for clearer imaging. The other, known as ‘Half.Turn CT’, is “a novel method for almost halving the angle through which a specimen rotates during the X-ray cycle, speeding the process without loss of image quality,” the manufacturer explained. The company says the new model is simpler to operate and has double the efficiency of its former CT systems – enhancing its suitability for a wide range of applications. “The intrinsic benefit of X-ray CT is that it allows both the exterior and interior of a sample to be inspected and measured non-destructively. The XT H 225 ST 2x, which has undergone thousands of hours of rigorous testing, is distinguished by its ability to be tuned to match the part under investigation so that optimal results are produced every time,” the company said.
Rotating.Target 2.0 maximises the quality of data collected and hence image resolution. It also doubles the running time before preventive maintenance is required, lowering costs and raising equipment availability. Spinning the target dissipates the heat generated by the small focal spot size more efficiently, enabling continuous generation of high power X-rays and a dramatic increase in scanning speed and resolution, without the need for cool-down.
There is a choice of four targets, easily interchangeable by the user onto the source tube. The reflection target is the standard option with a focal spot size down to 3 µm, providing the resolution and power for a wide range of applications. The rotating target on the other hand features a 3x smaller spot size starting from 30 W, allowing very crisp images to be maintained at high powers and reducing the time needed to scan objects. Alternatively, a transmission target gives a spot size down to 1 μm for even greater clarity. Lastly, a multi-metal target is mainly used at lower energy X-ray emission for material analysis.
Another new feature is Local.Calibration, which allows rapid, repeatable, automated calibration of voxel size at any CT scan position, rather than the user having to perform the function manually. It leads to a radical improvement in measurement accuracy. Extra benefits are that the procedure is deskilled and dimensional accuracy is traceable.
A further innovation centres on maximising the availability of the CT system by raising the lifetime of the filament. Auto.Filament Control intelligently controls the X-ray source to double the lifetime of the filament, lowering the cost and increasing system uptime without losing microfocus resolution. When the filament does have to be replaced, downtime is considerably reduced by the introduction of Quick.Change plug-and-play filament cups. The convenient, highly repeatable procedure deskills the process and eliminates human error. In addition, the filaments themselves have been aligned and conditioned by Nikon Metrology’s X-ray engineers to deliver optimal performance.
Additionally, the Half.Turn CT innovation means that instead of rotating the sample under investigation through 360 degrees during the X-ray cycle, it is only necessary to rotate it through just over 180 degrees to obtain sufficient data for an image of equivalent quality. Increasing data acquisition rate by 100 percent doubles inspection efficiency, which is especially useful in support of production applications.
An additional feature of the XT H 225 ST 2x is motorised FID (focal spot to imager distance) adjustment. The user does not have to increase X-ray power, which would make the focal spot larger, or lengthen detector exposure, which raises scan times, to compensate for the fact that X-ray intensity falls as the distance increases between the source and the flat panel detector. A shorter FID may be selected instead, giving faster scan times for a given resolution or a higher signal-to-noise ratio when using low energy X-ray power, the company said.
