555854 Franck - Hertz Tube

For demonstrating the discontinuous release of energy by free electrons upon collision with mercury atoms, and for determining their excitation energy. The Franck-Hertz curve is plotted either point-by-point with indicating instruments or continuously by means of a recorder or CASSY.
Vacuum tube with indirectly heated cathode, emission control grid, anode grid, collector and a mercury drop which vaporizes when the tube is heated.

Technical Data

•Filament: 3.15 V/0.4 A
•Grid voltages:
Emission grid: 0 - 4 V DC
Anode grid 0 - 40 V DC
•Countervoltage at collector: approx. 1.5 V DC
•Socket: 8-pole pin socket
•Mercury filling approx. 5 g
•Excitation energy of the Hg atoms 4.9 eV
•Operating temperature: approx. 200 °C
•Dimensions: 10 cm x 2.8 cm dia.

Please note: The Franck-Hertz tube (555 854) can only be used in conjunction with the corresponding sockets (555 864/555 865). It is not possible to operate it on the socket of the old Franck-Hertz tube (555 85, no longer available).