Public Lab Research note

This is an attempt to replicate an activity.

Thermal Images for Community Environmental College

by sara | July 18, 2012 14:31 18 Jul 14:31 | #2863 | #2863

Over this week, I'm working with Environmental Justice League's Community Environmental College. We are making thermal flashlights and experimenting with thermal images.

Yesterday we made four thermal flashlights. A step by step how to guide for wiring the thermal flashlight for electronics beginners we used is attached. While a group of 8 students worked together on making these, a second group experimented with thermal images. I've attached some of the images they created with the flashlight.

They tried varying the temperature range of the flashlight and imaging the same spot. The first image shows hot water pipes being imaged using the flashlight set to a range of 80 to 100 F. The red pipes clearly visible in this image were not visible in the first image they made of the pipes with the camera set to a range of 70 to 110.

So we could identify which colors correspond to which temperatures the students marked up color wheels with the min and max temperatures and then manually subdivided the wheel. It was pretty basic but it worked quite well.

They also tried imaging people in these different temperature ranges.

They noted that the results of the images varied a lot depending on the surface reflecting the color of the flashlight. The streaky third image was due to reflection of the LED from the back of the white door. They experienced similar troubles with reflective surfaces when trying to image an aquarium.

To make these images we blocked out all of the light in the basement of the Community Environmental College. Students also tested the flashlight as a thermometer to look for AC leaks from the outside of the building.

Working from the video available here, we plan to use the thermal flashlights on thursday to explore the results of varying the temperature range to look for: water damage, over heating circuits, mold. We aim to isolate the temperature ranges appropriate for imaging these different issues and create a short video similar to the one above showing how the flashlight can be used to image a variety of issues.

Files Size Uploaded
ThermalFlashlightHowTo (1).pdf 1.79 MB 2012-07-18 14:36:23 +0000
colorwheels.pdf 29.1 KB 2012-07-18 19:19:40 +0000


Those are some interesting problems with the reflection-- I wonder if they could be solved by switching the direction the LED points from pointing at the wall to pointing at the camera directly.

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Good thought Mat! This solution was actually proposed by Julian at EJ League, we're going to try it out on Thursday with some kind of defuser on the LED itself.

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damn this gateway error

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