Franck Hertz Experiment Neon

(Includes Data Logger)

The Franck-hertz tube consists of an electron-emitting cathode, two mesh grids for accelerating electrons and an anode plate for collecting electrons. It is filled with a low pressure gas. The mesh grids provide the accelerating potential to electrons and the anode is held at slightly negative potential to provide braking.
At low accelerating potential, the electrons gain kinetic energy and reach the anode plate with purely elastic collisions with the gas atoms. As accelerating potential is increased the gas atoms absorb energy as they are excited due to in-elastic collision by the energized electrons. Thus fewer electrons reach the anode plate and there is a dip in the plate current. These dips in current is observed at approximately fixed intervals of accelerating potential which demonstrate the presence of discreet or quantum energy levels in the Bohr’s model of atom.
In the present Franck-Hertz experiment with neon gas, the absorbed energy by neon atoms is released through photons having red-orange wavelength, which can be visually observed in band formations. The experiment can be performed in manual mode where the accelerating voltage and the plate braking voltage can be manually controlled in SK090. Also with sensors and data logger in Sk087 the accelerating voltage can be automatically varied and plate current measured & displayed graphically on PC

Features:

• Automatic and Manual mode of operation.
• Ignition layers are visible on tube window.
• Voltage and Current sensors are auto ID. (SK087)
• Free graph analyzer software. (SK087)
• Individual 7 segment display for Filament voltage, control voltage, Grid voltage and accelerating voltage.
• Traco Power Supply for data logger and sensor. (SK087)

Objectives:

• To observe the neon spectral bands formation in FranckHertz tube.
• To record the Franck-Hertz characteristic curve for neon.
• To study the effect of filament voltage and anode plate voltage on the characteristic curve.

Technical Data:

• Franck Hertz Unit : Mode manual or Data Logging, Voltage 1.2-12V, Display 3½ digit LED Screen Grid (G ) Voltage-80, Control Grid (G ) Voltage 0-10V, Filament Voltage 0-9V, 4mm safety socket used
• Neon Tube : Dia. 130 x 26 mm, Filament voltage 6 – 9 V, Control voltage 9V, Accelerating voltage Max. 80 V Counter voltage 1.2 -10 V, 4mm safety socket, 4mm Plug
• Data logger (SK087) : I/P channels 4, 6 PIN BT connector, resolution 12 bit ADC @ 100 ksps, Analog I/P0-5 V, O/Pchannels12 bit DAC, Analog O/P ± 12 V max 10 mA, Current booster 1A, Power connector 3PIN, DIN, USB cable
• Power Supply : 220V, 50Hz AC, output ± 12 V, 3 PIN DIN
• Voltage Sensor (SK087) : ±10V, 4mm socket, 6 PIN BT connector
• .Current Sensor (SK087) : ±100nA, 4mm socket, 6 PIN BT connector

Scope of Delivery:

• 1 Franck-Hertz unit
• 1 Neon tube with mount
• 1 Power Cord
• 1 Data logger
• 1 Power supply for data logger
• 1 Current sensor (± 100mA)
• 1 Voltage sensor ± 10V)
• 2 Flexible plug lead red
• 3 Flexible plug lead black
• 1 Flexible plug lead yellow
• 1 USB cable
• 1 Software CD disc