FRANCK-HERTZ EXPERIMENT WITH MERCURY Description and Specifications for Lab Tenders
FRANCK HERTZ EXPERIMENT WITH MERCURY.
FRANCK-HERTZ EXPERIMENT WITH MERCURY Franck-Hertz experiment will demonstrate the validity of the
Principle of quantization of energy. This experiment was very
important, from a historical point of view, because it supplied
the experimental data for confirming Bohr model ; Bohr was the
first physicist being able to infer the diagram of the electronic
levels of an atom.
This experiment can be carried out with Franck-Hertz tube that
can use mercury or neon. Both these tubes need a specific
power supply and an oscilloscope.
COMPONENTS
• Franck-Hertz tube with mercury filling and heater
• power supply unit
FRANCK-HERTZ TUBE WITH MERCURY FILLING AND HEATER
Free electrons will collide with mercury atoms and generate
energy in quantized packets. Excitation energy can be
determined via a cathode-ray tube under vacuum filled
with mercury gas, and some parallel fl at electrodes that
avoid distortions of field lines. Electrodes include a cathode
with oxides, heated indirectly and pierced to produce a
homogeneous electric field, besides an anode grid and a
collector electrode. This tube will be heated by a special heater,
to increase the probabilities of collisions between electrons
and mercury atoms. This heater is used to attain the vapour
tension inside the tube filled with mercury: it consists of a
metal box with silk-screen-printing diagram, ceramic insulated
sockets for connections, display windows, an orifice for
inserting a thermometer, insulated handle, and it also includes
a thermostat for adjusting temperature.
Characteristics
• Heater: 4-12 Vac/dc
• Grid voltage: 0-70 V
• Temperature range: 160-240°C
• Working temperature: 200°C
• temperature accuracy: ±5°C
• Dimensions: 240 x 169 x 150 mm
• Weight: 3.5 kg
POWER SUPPLY UNIT FOR FRANCK-HERTZ EXPERIMENT
This unit will supply the necessary voltage for powering tubes and
it also includes a DC amplifier for measuring collector current.
Acceleration voltage is output by the power supply unit; inputs
are available for anode current and acceleration voltage.
Characteristics
• Filament voltage: 4-12 V, variable continuously
• Control voltage: 9 V at 10 mA
• Acceleration voltage: 0-80 V
• Operating modes: manual, variable continuously
• Voltage control: 1.2 – 10 V, variable continuously
• Analog outputs
• Output signal: 0-12 V at 7 nA/V
• Connections: through sockets of 4 mm
• Dimensions: 160 x 132 x 210 mm
Supplied with THEORETICAL – EXPERIMENTAL HANDBOOK