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HELP - PTFE centering bead is stuck in HP 911E 3.5 mm sliding load from 85052B cal kit.

Question asked by drkirkby on Dec 2, 2016

I've got an 85052B cal kit, and somehow managed to get the PTFE centering bead stuck in the load when I was guaging it. I've tried everything I can think of, including putting the connector end down, and trying to get some air behind it with the slide. But so far I've never managed to get this out. See photos, which were taken in room lighting at night, with no flash or tripod, so they are not great, despite the camera and lens are pretty decent. But I think you can see the problem.


And now a couple of pictures taken in daylight. It is amazing what a few extra photons do!

Has anyone any suggestions of how I might remove the PTFE centering bead? I suspect I might need to take the load apart, but I don't know how to get it apart.


Other things I've considered, but have not tried have included.


  1. Putting it in the freezer, on the assumption that PTFE probably has a higher coefficient of thermal expansion than brass, so is likely to be easier to move.
  2. A vacuum pump on the 3.5 mm connector, and pull a bit of air through it [Edit, have sucked on it, I can see one can't do that]

Any other suggestions - other than send it to Keysight for repair, which will cost more than its worth.