Laser Barometer




About: If you think I am funny here try my twitter @BaconPuppets

They say a fish isn't aware of the water. Are you aware of the air? How about tectonic plates? Or temperature? Maybe sound waves or vibrations? Can you sense the truck a block away? With this simple device you can see the movement of the earth, the traffic in the street and the footsteps down the hall. The very clouds passing over your home will make it react. I cannot really convey how crazy sensitive it is. Point it down a hallway or across a basement and wonder at the invisible world of sound, pressure, vibration and temperature that surrounds you.

Step 1: Print

Step 2: All

Step 3: The

Step 4: Parts

Step 5: Assemble

Put a balloon over an empty soup can.

Step 6: Slide...

Step 7: Together

Step 8: Add Hinges

Resistor legs work well.

Step 9: Ready.

Step 10: Done

Push the laser's button and slide it into the ring. The ring will keep the laser on.

Step 11: Target

Point it at a scale and watch the invisible world that surrounds you. The longer the distance the more the beam will sweep. A gym, warehouse or football field is ideal. Be cautious. Just touching the can will make the laser wildly swing from the heat of your hand. Drill a hole in the can if you only wish to see vibrations like if you live near a fault in the earth's crust. Calibration is not included. Files can be downloaded for free here or at

I hope you find this useful.

Step 12:

Pardon the delay for files. I'm new here and it took a while to figure out. The ring prints upside down. Everything prints without support. I recommend a brim when printing. I used blue 1.75mm PLA from Reprap warehouse in Edmonton Alberta Canada and a .4mm nozzle. My printer is a plywood Repstrap I call "Monkey S#!t Fight" The file "laser barometer complete" is all the parts plated to print the entire barometer at one time. The parts are also available separately.



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    7 Discussions

    spark master

    1 year ago

    plastic straw taped to a stretched rubber membrane over an open jar works as well is cheaper and I did it so long ago I think I was singing soprano, and all Beach Boy tunes wit out a falsetto.

    1 reply
    Peterthinkingspark master

    Reply 1 year ago

    The straw version only has a throw of about an inch. This can move a pointer a couple feet just down a short hallway. Many times more sensitive.


    1 year ago

    i like it, but if it's so sensitive, how can I determine what's causing it? is it the earth? or a train near by? thanks.

    4 replies

    Reply 1 year ago

    You can put a thermometer beside it. If there is no change in temperature then it is atmospheric pressure or vibration. Pressure changes are long slow sweeps up and down. Vibrations are short fast movements that return to the point they were on the scale a second ago. A yard stick or tape measure make a good scale. Placement is important too. Putting it on a concrete basement floor is obviously better than on a shelf on the second floor of a house.


    Reply 1 year ago

    What do you mean by "If there is no change in temperature then it is atmospheric pressure or vibration"? I guess when you are touching the jar, it is rather the vibrations from the touch that causes the swinging than the heat from your hand? Assuming the jar is air tight, both the pressure and temperature will affect the volume of the trapped air under the balloon and causing it to rise or fall. This is as you point out a slow process compared to the vibrations (but it will shift the 0-point if you are trying to measure ground vibrations). With a hole in the jar, the pressure and temperature should not affect at all and the 0-point will be stationary. But isn't the balloon acting as a drum skin and vibrates from sound waves in the air? And maybe also to small air currents? Is it sensitive to sounds? Really cool idea though and nice instructable! :)


    Reply 1 year ago

    Moving the can does cause vibrations but the heat from your hand will make the pointer swing up quite a lot. Well over a foot if you hold it for more than a few seconds. It is very sensitive to pressure and temperature. Yes the balloon picks up sound in the room. Foot steps more so. You can sing to it and make the pointer bounce around if you like but you would look quite crazy. Air currents, small children and cats will all make this challenging to use. But the air currents change the temperature of the can more than they blow the pointer around. I am glad you like it. It is interesting to "see" the atmosphere thicken and thin over my house. I hope to figure out a way to see which way the pressure is trending. Maybe an Arduino counter attached to a few solar cells.


    Reply 1 year ago

    I've toyed with the idea of hooking up an Arduino and some light sensors to log data but I keep getting distracted. Due to the fuzzy nature of the cheap laser pointer dot I think the cell would gradually increase output as the pointer swept up onto the cell. This would allow me to see if the dot was trending up or down by comparing it to another cell. But I am not at that point yet in my Arduino skills.