Your students will quickly gain an appreciation of the landmark Franck-Hertz experiment, which demonstrates the existence of quantized states, using this self-contained apparatus. The experiment can easily be performed in one lab period because the use of argon as a filling gas for the Franck-Hertz tube eliminates the need to wait for the tube to reach a high temperature, and the compact design with all voltage supplies built in and all measurements available on two panel meters gets rid of the time-consuming setup of tube connections.

The experiment is easy to conduct and data can be recorded either manually or automatically. When plotting the Franck-Hertz curve manually, the anode potential is finely adjusted between 0V and 100V by a ten-turn potentiometer and displayed on one panel meter, while the anode current is monitored on a second panel meter. Seven clear minima and maxima can be plotted. An automatic scan setting is also provided to allow the Franck-Hertz curve to be displayed on an oscilloscope operating in X-Y mode or captured by a computer interface system.

The apparatus is housed in a rugged metal case that can withstand many years of lab use. It measures 40 x 24 x 14cm. Power requirement: 115VAC. 1.8m long power cord included.