University of Alaska Fairbanks

Used in Lab:

This item is NOT used in any lab experiments.

Equipment:

• Reubens Tube                     Location: Demo East Sink
• Speaker                               Location: Demo Rm Shelf K
• Amplifier                              Location: Demo Rm Shelf K
• Frequency Generator          Location: Demo Rm Shelf K
• Separate power source       Location: Demo Rm Shelf K
  
• Wires                                   Location: Demo Rm Shelf V
• 2 Lab jacks                             Location: Demo Rm Shelf W
• Propane nozzle                   Location: Demo Rm Shelf O
  
• Propane                              Location: Demo Rm Fire Safe
• Foam propane holder          Location: Demo Rm Over the Fire Safe
• Lighter                                 Location: Demo Rm Shelf O
  
• Demo Rm Cart
  

Setup Instructions: (Estimate 30 minutes prep time, practice strongly recommended)

• Place the Reubens Tube on the Cart and wheel it next to the lecture podium
• Place lab jacks under the Reubens Tube block holders so that the tube is level
  
• Secure the propane nozzle onto the end of the tube and ensure it is in the off position.
  
• Place the foam propane holder next to the nozzle so the bottle won't roll off the podium
• Secure the propane bottle to the nozzle. Check again that it's off.
• Check the balloon on the other end of the speaker - if it is cracked it may need a replacement (Shelf W)
  
• Set the speaker in front of the balloon end of the tube.
• Connect the frequency generator in series with the amplifier and the speaker.
• Connect the amplifier to a separate power source (~6V)
• Bring the moveable air return (REIC 201, 202) directly over the tube -  this will neutralize drafts
  
• Light the lighter and hold over the tube holes as you slowly turn on the Propane.
• Watch the nozzle for frost - if frost forms immediately turn off the propane. This happens when there is too much flow of propane and the heat of condensation cools the tube too fast. You will end up with liquid propane that will suddenly flair up.
  

Apparatus Notes:

Make sure it's level. You need the amplifier to be wired right because there will not be a loud enough sound wave without it.
It's finicky to operate but a crowd pleaser. See Jeanie for setup help if you haven't done it before. Do not attempt this demo outside, any breeze interferes with the wave.