Franck-Hertz Apparatus 

[Mercury]

The Franck-Hertz experiment was an important experiment in atomic physics conducted by James Franck and Gustav Hertz in 1914. This experiment proved that atoms absorb discrete (quantized) amounts of energy. In this experiment, electrons are accelerated towards a tube filled with mercury vapor. When the energy of the electrons is sufficient to excite the mercury atoms (about 4.9 eV), inelastic collisions occur which cause a decrease in the measured current. The results of this experiment supported Bohr's atomic model and became the first experimental proof of quantum theory.

Specifications: ..

Mains voltage: 230 V ±10% (50/60 Hz)

Filament voltage UF: 0 V − 12 V continuously adjustable

Heater current: 0 A − 2.5 A  

Control voltage UG: 0 V − 12 V continuously adjustable

Accelerating voltage UA: 0 V − 80 V continuously adjustable or sawtooth

Retarding voltage UE: 0 V − ±12 V continuously adjustable, switchable polarity

Output UY for collector current IE: IE = UA * 38 nA/V (0 V − 12 V)

Output UX for accelerating voltage UA: UX = UA / 10

✅Condition: Good