The iNSIde View

You may be wondering what 4D Computed Tomography (CT) is and how does it differ from 3D CT? With 3D CT you will generate a 3D volume of your sample that you are able to rotate, slice through it and adjust your histogram. 4D CT will give you the same benefits as 3D CT, but with the added bonus of motion and time. Sample motion can be captured by either two different scanning techniques, static or dynamic.Static 4D CTStatic 4D CT is the method of creating 4D CT by acquiring multiple CT scans. This is a lot like stop motion animation where a scene is captured and then slight movements…

What is pixel binning? Pixel binning is a mode that the X-ray detector can run in that takes a 2x2 matrix of pixels and combines them to create one larger pixel. This is done in the hardware internally in the detector so there is no additional processing time for the computer. There are a number of benefits to using pixel binning including better signal level, higher contrast, and faster framerates. The down side to using pixel binning is that there is a loss in image resolution. This decrease in resolution may not have much of a negative effect though, as the contrast sensitivity that…

When performing Computed Tomography, a common artifact that frequently pops its ugly head is a ring artifact. A new Hardware/Software solution from NSI nearly eliminates ring artifacts completely while bringing other benefits to the acquisition process.During a CT scan, pixels that do not respond to the variations in product related attenuation will cause consistent or intermittent tracks along scan trajectories which end up as rings in a CT reconstruction.Another contributor to this artifact is product position. The area of a part that lands directly on the center of the rotational axis has no real…

Standard cone beam scanning is sufficient for many applications, but what about the applications where you cannot fit the part in a single detectors view? Physical size of a sample can be a limitation when trying to achieve a given resolution, or you may be dealing with artifact issues. All of these limitations are the reason that NSI has developed advanced scanning styles to overcome issues you may run into when a challenging application comes in.Vortex scanning is a commonly used scanning style by our NSI experts when a sample is very tall in one direction, such as a baseball bat. When looking for measurement…

According to the International Vocabulary of Basic and General Terms in Metrology (VIM) [1], the traceability of a measurement result is demonstrated through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty. This means that not only is it necessary to use a reference standard of length which has an unbroken chain of calibrations, but the uncertainty of the resulting measurements must include the uncertainty of all the links in the calibration chain.While the VIM definition is clear about what is needed for the traceability of a measurement result, it does not…

My name is Ross Johnson and I am the “New Guy” to NDT. Now when I say “new” I mean BRAND NEW. After college I started a woodworking business and for a few years I built everything and anything from skateboards to banjo necks. I had jobs in machine shops running Bridgeport’s and lathes and then I moved into Product Development. My time in Quality Control was always limited to comparators, CMM and gages. And because there were never any requirements for non-destructive testing in our industry, I never learned about the different types of NDT. My first experience with X-ray was the X-ray I had of my broken pinky…

In the fall of 2015, NSI opened an Inspection Services and systems demonstration lab located at 16170 Scientific Way in Irvine, California. Now that the paint is dry and the construction complete, we were fortunate to host the first of many open house events on February, 24th as well as an overflow event the following week. The event was put on in conjunction with Instron, our sister company, who makes world class material testing systems. Attendees were hosted and saw presentations from NSI on CT scanning of additive manufactured parts as well as live demos of digital X-ray and CT scanning technology. Instron presented…

X-ray micro computed tomography (micro-CT) is a powerful tool for material characterization as it can non-destructively and non-invasively image the internal structure of an object. This enables the wide range of characterization and inspection applications in the areas of biomedical, aerospace, automotive, and many more.With the recent development of novel reconstruction algorithms, we can not only image the object in 3D but also record how its structure is varying over a period (i.e. 4D imaging, as a software add-on offered by NSI).In a typical computed tomography (CT) set-up, a micro-CT image is generated…

To the young, thirty years seems like an eternity, then one day you have your 30th birthday and the years go by unbelievably fast. From what I have been told, people in their golden years see thirty years as a blink of the eye. I guess it’s all relative to your age and perspective, but in this day and age, thirty years in business is something to celebrate. Although I personally haven’t been with NSI for the full 30 years, I have been around for a good chunk of them and have seen quite a change in the business by both choice and requirement. So how does a business last and why is NSI still here when so many…

Before choosing an area to scan on your sample you must first have an idea of what you are looking for, because you will need enough resolution to see the area you are interested in. If you have a sample with a 40 micrometer defect, you’ll want to have multiple pixels to represent that defect. Often times the defect size in the sample is not known, but an estimate based on your sample knowledge is very helpful in this process. If your full sample size is 2 inches by 2 inches and you are using a 127 micrometer pixel pitch panel, you can expect to achieve around 7.5X magnification, giving you an estimated…