Have students open the Stern Gerlach simulation on their computers
Ask them what each object in the simulation represents
Explicitly remind the students that random atoms come out of the oven, so without the first device we would not be able to select a beam consisting only of atoms deflected up when the inhomogeneous magnetic field is aligned along the z-axis.
Once a beam is 'prepared' with a certain spin, then we can use a second device to analyze the spin - hence the names 'state preparation device' and 'analyzer'
Have students set up the situation shown in slide 12, and run the simulation to make sure they can run the simulation before starting the lab.