Welcome to Shadelab.

Calipers? Is that a type of bug?

No. A caliper is a device used to measure the distance between two opposing sides of an object.  We used them to measure tree trunks and balloons!

How do you make a caliper?
You can make a caliper out of almost any material you want. You can make it from cardboard, paper, foam, wood, or even from an old tire you have. In order to decide on the material, you need to know what you are measuring. You can’t imagine how useful calipers can be! You can measure the width or diameter of almost anything you want no matter how big or how small.

Why did we measure tree trunks?
Well, we needed to calculate the amount of carbon dioxide a tree can intake. In order to do this, you need the tree type and its trunk diameter. The trees we measured were at Humboldt Park, in an eight block radius. It was a big place with a lot of trees so we made three calipers in different shapes.

One of the calipers was built in an “F” shape; the other two were built in an “O” or a” U” shape. The materials we used were cardboard, foam, and an old tire. We then used tape, string and some zip ties. The calipers we made could measure trees with diameters of up to 50 inches. They looked cool and interesting.  Needless to say, they grabbed people’s attention while walking in the Humboldt Park area. It was fun carrying the big calipers around, but the most fun part was building them as a team.