Ion gauge filament replacement is needed when the filament comes to the end of its effective working lifespan. The exact lifespan depends on a number of factors including the material that the filament is comprised of and the residual gases present in the vacuum system.
Ion gauge filaments are generally made from either Tungsten or Iridium. Where Iridium is used, it can be coated in either Thoria or Yttria. Replacement Tungsten filaments tend to be cheaper, but they are also more brittle, meaning that they need to be changed more often, particularly if the vacuum gauge unit is moved. To replace a vacuum gauge’s Tungsten filament, you need long nosed pliers, side cutters, an Allen key (often supplied with the replacement filament), isopropyl alcohol and cleanroom gloves. Before starting the process, the pliers and cutters should be cleaned with the alcohol. The alcohol can also be swabbed on the setting screws to improve lubrication. The feedthrough wire should be supported with the longnose pliers while the Allen key is used to undo the filament support screw. Then loosen the remaining support screws; this will enable you to remove the old ion filament assembly. Next, remove the new assembly’s restraining sleeve and fit the centre support into the barrel connector. Once in place, tighten the screws. Continue by holding each ion filament termination with the pliers and extending them down to the outer barrel connecters. These should them be fixed in place with the set screws. The method for vacuum gauge Iridium filaments is similar, but you should always refer to your manufacturer for specific instructions.
If you are looking to source a high quality ion gauge filament for your UHV system, then visit Arun Microelectronics Limited at http://arunmicro.com/. Our products are supplied with grub-screws, hex key and full installation instructions. However, if you have any questions about any of our products, please email email@example.com.