Re: How can I measure the speed of sound with the Kunt tube?

Hi,

Your problem of finding information is due to the fact that Kundt is 
written with "dt". A search for "kundt tube" reveals a plethora of links.

The tube is a transparent tube with a small amount of cork dust along the 
inside (or any other powder with low volumetric weight and that doesn't 
stick together). One end is terminated by a transducer (loudspeaker), the 
other end by a movable plunger.

Measuring the velocity of sound proceeds as follows:
*Feed a sine wave of known frequency into the loudspeaker.
*Move the plunger until a standing wave pattern appears. The cork dust 
will visualise this by settling down at the speed minima (=pressure 
maxima) as on any other spot it gets moved by the moving air.
From this, you can count the number of half-waves (=number of nodes). 
Knowing the length of tube between the transducer and the plunger then 
allows you to calculate the velocity of sound in the tube (which is 
practically the same as the velocity of sound in free air).

An illustration is at
njc

Regards,

Bruno