Oscillations and Waves > Instruments > Air Columns DCS# 3D32.25

PRESSURE VARIATION IN CYLINDRICAL RESONATOR


APPARATUS
1.2 m brass tube 202-06-C
speaker 202-07-E4
HP audio generator 202-08-G
Radio Shack amplifier 202-09-B
condenser microphone on a stick 202-06-C
oscilloscope with video camera 202

DESCRIPTION
Tune the oscillator to a resonance frequency of the cylinder and move the microphone along the axis of the cylinder to show alternating pressure nodes and antinodes.

For a closed tube, use a clear plastic resonance tube with a wooden stopper (113-03-B).  One of the stoppers has a hole in it for the microphone.


NOTES

Microphone requires 3 AA batteries which should be removed after use, as it has no on/off switch.

Clip a lead from the scope ground to the cart to eliminate 60 Hz interference.