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Identify this piece of equipment?

  1. Dec 15, 2015 #1
    We were digging through some of the apparatus today and amongst a few dual beam tubes we found this, pictured below


    Here's another one up close:

    It's very similar looking to a dual beam tube shape-wise but as you can see the internal structure is quite different. What is this? After looking at it for a while we suspect it might have to do with measuring the charge of an electron (a sort of revised Millikan experiment?) but we can't really tell

    I've tried searching it up but as you can imagine I had a hard time describing it to a search engine without really knowing what it is, so that wasn't too useful.

    Can anyone shed light on this? Thanks
  2. jcsd
  3. Dec 15, 2015 #2
    Similar to a cathode ray tube.
    I can not find that exact design but it seems they come in many different shapes, sizes and configurations.
    cold cathode ray tube of sort.
    Last edited: Dec 15, 2015
  4. Dec 16, 2015 #3
    I can imagine it sitting between pairs of Helmholtz coils as a demonstration of the Lorentz force or between electrostatically charged plates to demonstrate the Coulomb force or some combination, particularly if the gas in the tube glows when ionised.
  5. Dec 16, 2015 #4
  6. Dec 16, 2015 #5
    It is a demonstration thermionic diode used in education.
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