Electromagnetism & Motors

e/m Tube Only


[Product Description]

Glass-vacuum tube with a built-in phosphor coated engraved glass rod with a scale (Replacement tube for E/M apparatus)

[Overall Advantages to Users]

  • Built-in scale for measuring the path traced by the electron beam.
  • The graduations and numerals of the scale are illuminated by the collision of the electrons, making observation and reading even easier.


  • Specific charge of electron
  • Electric charge of electron



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[To all users]

  • Glass vacuum tube has a built-in phosphor coated engraved glass rod with a scale along the central axis, which eliminates parallax when making diameter readings of the electron orbit.

[To teachers]

  • Helium gas sealed within the tube facilitates the production of a bright, clear view of the electron beam.

[To students]

  • Built-in electrode in the tube absorbs electrons after being emitted from the electron gun and traced their circular path, which prevents the circular tracing of the electron path from being disturbed by previously emitted electrons and/or becoming in spirals, contributing to more accurate measurement and extended operating life of the discharge tube.
  • Dimensions: 5″ diameter (12″ total length)
  • Helium gas filled
  • Built-in Integrated phosphor scale
  • Heater: 6.3V, 1A
  • Maximum Ratings:
    – Plate Voltage: 500V
    – Plate Current: 10mA
  • Tube Life: 100+ hour range (depending on operating conditions)

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