The iNSIde View

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…

When determining the number of projections you need for your CT scan you must first know some information about the sample that you are scanning. Samples with complex geometry will require more projections than samples with simple geometry. The reason for this is that if the sample has a flat surface we must get a projection during the CT scan that lines up with that flat surface in order for us to get a reconstruction that shows that surface as flat. If you do not get a projection that shows the flat surface in the scan, you will see that surface as bowed or curved slightly in the reconstruction. If the sample that…

When performing Digital Radiography and Computed Tomography, a common issue all of us deal with is the balancing of exposure time and signal to noise ratio (SNR). SNR simply compares the level of the desired signal to the level of the undesirable background noise within an image. SNR is therefore the result of dividing the average (mean) signal by the variation (standard deviation)

In today’s competitive global market, engineers are faced with the ever growing challenge of balancing the functionality, complexity, reliability, safety, aesthetics and cost of a product’s design while bringing it to market faster than anyone has done before. Digital radiography (DR) and Computed Tomography (CT) give the modern engineer tools like no other. Analysis, reverse engineering, model building and communication all benefit from DR &CT X-ray technology.

As aerospace suppliers enter into the world of digital radiography, there may be some obstacles with customer approvals. Receiving customer approvals for production using digital X-ray can be easier when following this recommended path. The scenario of transitioning from film based radiography to a digital radiography system has been recently seen as the chicken or the egg. Which one came first? Since the mid 2000’s suppliers have questioned investing in capital equipment. How can the supplier invest in capital equipment unless an…

When I first began working at NSI in 1998, I clearly remember one of my first visits to a testing laboratory in Wisconsin. That particular company was interested in converting their X-ray film systems to digital detector technology-based systems. Nearly all of their radiography work involved the inspection of castings for voids and shrink, making the utilization of a digital detector very practical with the opportunity to show a great savings in a short term. At the time, the technology had just been released and I really knew very little about digital technology in general; my father-in-law had just purchased a digital…