What does hermeticity mean, how is it defined and tested, and what is the difference between hermetic and quasi-hermetic packaging?
We live in a world in which seeing is the most important sense. From screens to road signs, many objects that surround us every day would lose their purpose if we could not see them. Yet, there are even more things we cannot see than things we can see. Be they very small like viruses, bacteria or even atoms, or very distant like the stars of other galaxies.
It can be especially challenging to see in harsh environments with high temperatures, dangerous or chemically volatile substances, or areas not accessible to humans. However, various branches of industry need to be able to see in these particular places.
Tokamak fusion reactors, for example, use a powerful magnetic field in a ring shape to confine hot plasma. This presents a very challenging environment for imaging, as the strong magnetic field of the reactors will erase images acquired with a traditional digital camera. Another example is steel mills, where temperatures are hot enough to melt plastic and prevent digital cameras from operating properly. Nevertheless, it is necessary to check for spills when cranes are transporting hot fluid iron in large buckets.
For these tricky environments, image bundles can offer a flexible, but robust solution. They can be used in tight spaces and also withstand high temperatures and hazardous chemicals. At the same time, they do not interfere with electricity or react to magnetic fields. Because they use light and no electricity, optical fibers can reach distant positions and close gaps between a camera and an area that needs to be imaged.
These image bundles consist of thousands and thousands of wafer-thin glass fibers, with each individual fiber guiding exactly one pixel. To transport an entire image, the fibers at the beginning and end of the cable must be arranged in exactly the same configuration.