X-ray CT system has faster process with clearer imaging, says Nikon Metrology

Five features distinguish the XT H 225 ST 2x micro focus x-ray computed tomography (CT) system, says Nikon Metrology. Two of these features are not available on any other industrial CT system, the company believes.

An advantage of x-ray CT is that it allows both the exterior and interior of a sample to be inspected and measured non-destructively. The 225kV XT H 225 ST 2x can be tuned to match the part under investigation to produce optimal results.
One feature, believed to be unique to the XT H 225 ST 2x is Rotating.Target 2.0, which uses efficient cooling to enable a three times smaller focal spot size for clearer imaging. The other is Half.Turn CT, 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, claims Nikon Metrology.

The efficient system can be used for a wide range of applications from the museum laboratory through to academia and the R&D department as well as the factory floor.

Rotating.Target 2.0 maximises the quality of data collected and therefore image resolution. It is also claimed to double 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 onto the source tube. The reflection target is the standard option with a focal spot size down to three micron, providing the resolution and power for a range of applications. The rotating target has a spot size which is three times smaller starting from 30W, 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 one micron for even greater clarity. 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 improves measurement accuracy and also ensures that the procedure is deskilled and that dimensional accuracy is traceable.

Increasing the lifetime of the filament maximises the availability of the CT system. This is achieved by Auto.Filament control which controls the x-ray source. When the filament does have to be replaced, downtime is “considerably reduced” with Quick.Change plug-and-play filament cups, says Nikon Metrology. The highly repeatable procedure deskills the process and eliminates human error. Filaments are aligned and conditioned by Nikon Metrology’s engineers.

The Half.Turn CT means that instead of rotating the sample under investigation through 360 degrees during the x-ray cycle, it is only needs to be rotated by just over 180 degrees to obtain sufficient data for an image of equivalent quality. Increasing data acquisition rate by 100 per cent doubles inspection efficiency, notes Nikon.

An additional feature is motorised focal spot to imager distance (FID) 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 falling 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.

Nikon Metrology’s in-house developed Inspect-X software is designed to streamline the process of acquiring and reconstructing CT data for accurate inspection. Siutable for use by novices, operators are offered only the information they need at any moment, simplifying the task. Advanced users can take advantage of full control over all settings of the source and flat panel detector, as well as over acquisition techniques and settings, to tailor the system to the sample being scanned.

http://www.nikonmetrology.com