Image Intensifiers
North Star Imaging provides the widest range of image intensifiers available anywhere. New and reload intensifiers from 4-inch to 16-inch are available. And as always, North Star Imaging offers quality service to assure the best solutions for you.
What is an image intensifier?
Image Intensifiers by themselves are an analog device. When used with a digital image processor or digital camera, they are the most common digital technology currently being used in the evaluation of castings. Intensifiers are being used both in foundry control evaluations and full inspection of product. In short, the image intensifier converts the x-rays into white light, which is viewed by an analog or digital CCD or CMOS camera. This image is then displayed on a monitor either processed or unprocessed. Images can be captured at nearly any frame rate depending on the camera configuration. Most cameras are configured to operate in a real-time mode of 30-60 frames/second allowing in motion evaluations. Others cameras have adjustable frame rates. Slow frame rates (1 fame /sec) can be used to acquire more x-ray flux at lower energies on a static exposure to produce a very clear image. High-speed camera systems can be employed at extremely high frame rates to provide real-time imaging of parts, product or processes in motion at speeds that would be blurred to the human eye. For example one can watch solder flow into an internal joint or watch liquid metal flow through a casting mold. This process has been used to help correlate the actual metal flow to a computerized flow model. 8-12 bit images are available depending on the camera configuration. Intensifiers allow for high throughput when combined with a programmable material handling system. Intensifiers vary in size of viewing area in a typical range of 2” to 16”. The most common used in the inspection of castings are 9 and 12-inch systems. Intensifiers can come equipped with multi field viewing capabilities allowing the field of view to be changed electronically to provide additional magnification. Intensifiers can provide extremely good sensitivity but at the expense of overall field of view when geometric or electronic magnification is used.
When comparing intensifier spatial resolutions it’s important to be careful to consider the systems field of view relative to its LP/mm. For example a large FOV system may only be capable of 1-2 LP/mm with the gauge mounted on the intensifiers input. In contrast, a small 1.8” intensifier can provide 8-9 LP/mm. The smaller unit provides great resolution but its applications are very limited due to its size. One negative of intensifiers that needs to be accounted for at higher energies is image blooming. If a part edge, a through hole or a significantly thinner section of material is exposed to the high energy, beam blooming occurs and can washout the image in that area. This is usually compensated for to a degree by masking or in the use of shutters. Intensifiers do degrade over time, requiring reloading or replacement. In most applications, when used properly they will typically last for a good number of years without significant image resolution loss. At 1 to1 geometric magnification most intensifiers provide less resolution than the digital detectors and CR plates.
Custom-tailored performance
As a Supplier of the world’s leading producer of X-ray image intensifiers, North Star Imaging gives its customers the broadest range of performance in terms of image quality (resolution, DQE, contrast), format and housings. This reflects North Star Imaging’s focus on meeting the specific needs of each inspection system, either mobile or stationary, through proven custom-tailored solutions (format, housing, attachment type, etc.).
