Public Lab Research note

Balloon Mapping K Week

by jbreen | October 09, 2013 01:29 09 Oct 01:29 | #9423 | #9423


K Week is what the University of Kentucky calls the week before Fall classes start, when the University pulls out all the stops to welcome the incoming freshmen to college life. Campus is awash in free pizza and t-shirt giveaways and the College of Arts & Sciences holds a welcome fair replete with academic demonstrations. Not to be out done by the Chemistry Department, who were demonstrating the explosive potential of dry ice by heaving increasingly sizable chunks of the stuff into a trash bin full of water, we in the Geography Department brought out our coolest toy, a Public Lab Balloon Mapping Kit.
As is often the case with demos, we had a few technical difficulties. We had to use two balloons to loft the camera, the cause of which seemed to be two-fold.* 1) We had a heck of a time trying to figure out when the balloons were fully inflated. I was taught an ingenious trick for figuring this out when you have a wall available (yes, yes, I'll write that up soon), but it doesn't work out in the field. 2) Helium intended for use in party balloons is supposed to be about 94% pure, but we may have gotten a bad batch. Even with my dubious math skills, I'm pretty sure the balloons should have contained more than enough helium to easily loft themselves, the 198 gram camera and the attached line.
And so, I pose to the collective hive wisdom of Public Lab the following questions: What tips or tricks do you have for measuring when you've got the balloon fully inflated? Have you ever gotten a questionable batch of helium? Is there someway to test the quality of your helium before you find yourself with an under-performing balloon?

*That our pair of balloons happened to be white and orange, the colors of a much despised rival school to the south of Lexington and therefore a near criminal offense on the UK campus is another matter entirely.


Ooh. The colors, eh. Uf.

Im writing a note about using a berkley fishing scale to measure the lift of the balloon. But flickr is down.

I think there was a not on how much lift the balloon should have, which i hope to find. And i hope that lift is in kg, because those are the units what my berkley scale measures force in

Someone mentioned at the barnraising that the lift should at least be 2x the payload. For a kite anyway.

Thanks for posting, i repeatedly have this problem with the balloon.

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We don't mess around with school loyalties here at UK. :)

I hadn't considered the fish scale idea, though that seems like it would work. I had thought of carrying something that I could use to measure the circumference of the balloon, since I know that the balloon when fully inflated has more than enough lift. The key is that I need a method that I can do by myself while holding the balloon.

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