[Phys-L] Quincke tube acoustic interferometer apparatus

[Larry Smith <Larry.Smith@snow.edu>]

Phys-L:

We built an “acoustic interferometer” (a.k.a. “Quincke tube”?) much like the 
one shown in Figure 18.5 on p. 548 of Serway and Jewett’s “Physics for 
Scientists and Engineers” 6th ed. We designed an experiment much like the one 
shown in the first video of
https://instructional-resources.physics.uiowa.edu/demos/3b5540-interference-quinckes-tube-or-trombone

However, when we ran the experiment ourselves before foisting it on the 
students we found many more resonances (ramping up the frequency for a given 
∆r) than simple path length difference would predict. We wonder if we are also 
getting single-tube standing waves.

Has anyone run a successful acoustic interferometer lab with students?
Are you willing to share?
Do you have any insights on why we got so many resonances?
Is Quincke tube the right name for this?

Thanks,
Larry