Seeing Chemistry in a Different Light—FLIR Thermal Cameras in the Classroom

infrared image of the process of dissolution

One of the inherent challenges of teaching chemistry is to make the invisible, visible. Often, we try to overcome this barrier by getting creative with a variety of models, animations, and simulations to help students think about chemistry in a way that is easier to conceptualize. The creative endeavor to make an abstract idea more concrete is a challenge that I’ve always loved pursuing. So, when I was presented with the opportunity to use some of our science budget to purchase a couple , I was immediately curious about its potential for supplementing my instruction (see figure 1). To my surprise, having access to this piece of equipment has created several opportunities to experience the richness of chemistry in ways I had never been able to offer my students—or myself. While I know its potential applications in the classroom go well beyond my own, I wanted to share some of the ways I have found it to be helpful.

 

Figure 1: FLIR ONE thermal camera

 

Before trying to use a piece of equipment, it’s worthwhile to have a basic understanding of how it works. To put it simply, FLIR cameras primarily deal with the infrared (IR) part of the EMR spectrum. The camera detects infrared energy (heat) and converts it into an electrical signal, which is then processed to produce a thermal image on a video monitor. Since all objects emit infrared energy to some extent, a thermal camera can easily detect differences in heat between objects in addition to quantifying that heat as a temperature reading.

Though the initial target audience for this technology may have been the military, it was only a matter of time before advancements in technology would allow for its use to cross over into a variety of avenues. The FLIR One camera is a wonderful example of this.

Depending on your need, FLIR offers three different types of connectors (USB-C, micro USB, and Lightning), which means it can connect directly to nearly any phone or tablet. If you are at a school with 1-to-1 iPads, this means any student would have the ability to use the camera on their own device. Using the FLIR ONE camera requires the free FLIR ONE app to work. The app is fairly easy to use, and it allows you to capture not only pictures, but videos as well. Additionally, you can record multiple temperature readings by touching any area on the thermal image. Once installed, it’s simply a matter of turning the camera on, opening the app, and start looking at the world.

Okay, enough background—how can this thing actually help teachers in the classroom?

 

Figure 2: Dissolution of NaOH (left) and NH4Cl (right) as seen with FLIR One camera

 

Visualizing the heat of solution (endo/exothermic)

This was the first application that came to my mind. When I would demonstrate endothermic vs. exothermic processes in the past, I would simply dissolve two solutes, display the temperatures on the board up front, and students would see how temperature changed. It’s not like there is anything wrong with this; it gets the point across. However, this year I filmed the process with my FLIR camera and projected my phone screen to the board. Not only were students able to see the visual difference in thermal energy, they could still see the different temperatures as well. Combining these two pieces of evidence provided a much more fruitful conversation than in the past. In figure 2, you can see the infrared image we recorded while observing the dissolution of NaOH (left) and NH4Cl (right).

 

Figure 3: Crystallization of sodium acetate (right) compared to beaker of water (left)

 

Crystal Formation (Supersaturated Solution)

This was just awesome (see figure 3). The idea to film the crystallization of a supersaturated solution of sodium acetate was the product of one of those “I wonder if…” ideas (see video 1). Near the end of the video, I decided to lift the beaker up since I thought some of the energy released from the crystallization would have dissipated into the lab table. This moment was a perfect example of the potential for this tool to enable curiosity and make connections with different concepts.

 

Video 1: Supersaturated sodium acetate with FLIR camera (Ben's YouTube Channel - Published Nov. 8, 2019. Accessed 1/14/20)

 

Comparing Heat Absorption

Figure 4: Thermal image of burning hot dog coated with fire gel

This was inspired by Tom Kuntzleman, co-author of the JChemEd article .1 During our end-of-year research project, a group of students wanted to investigate the insulating ability of the superabsorbent polymer, sodium polyacrylate. The group combined this polymer with water to make a gel-like substance (fire gel) and coated a hot dog with it. The idea was to light two hot dogs on fire (one with and one without the fire gel coating). By doing this, the group was able to confirm Tom’s data and actually supplement the evidence with a visual of thermal energy. It was cool to actually see the insulating effects from this point-of-view.

Figure 5: Comparison of hot dogs after burning with gel (left) and without gel (right)

 

Strength of Intermolecular Forces (Evaporative Cooling)

I haven’t done this with the FLIR camera yet, but I definitely plan to once we get to the appropriate unit. Usually, I’ve seen this demo done on a lab table and students are able to see the alcohol disappear before the water. Alternatively, some teachers have students place temperature probes in different solutions and then record differences in temperature while evaporating. Both approaches serve a useful purpose and allow for important inferences to be made. Supplementing this demo with a thermal camera brings in a new perspective, which was otherwise invisible.  is an example of how a simple experiment on this topic could be performed.2

 

Figure 6: Comparing the effectiveness of IR absorption by different greenhouse gases 

 

Comparing the Effectiveness of Different Greenhouse Gases

This idea was inspired by an activity from , and I absolutely love it. A group of students wanted the focus of their investigation to surround greenhouse gases. So, with a bit of guidance, I introduced them to the idea that they could trap various greenhouse gases in a bag and see how effective each gas is at absorbing infrared energy (figure 6). To do this, they simply placed the bag of gas in front of their face and captured a thermal image. If the gas does not absorb infrared energy all that well, that means more of it will pass through the bag and into the camera, resulting in their face to be visible. Conversely, if the gas absorbs infrared energy effectively, their face will appear nearly opaque since most of the energy was absorbed and not allowed to pass through the bag. I believe the gases that they tested were air, carbon dioxide, methane, and tetrafluoroethane. This was a really fun application and I enjoyed watching the group of students do this throughout their investigation.

I haven’t even had this FLIR camera for a whole year yet and I’ve already been convinced that it can supplement my instruction in ways that are directly beneficial to student learning and curiosity. Because it is easy to use, it lowers the threshold for experimental skills that may have been needed to conduct an authentic science investigation. I have no doubt there are hundreds of other ways to utilize this technology. So, if you have some ideas, please share!

 

CITATIONS

1. Kuntzleman, T.S., Mork, D.J., Norris, L.D., Maniére-Spencer, C.D., , J. Chem. Educ., 2013, 90, 7, 947-949. (accessed 1/14/20)

2. , Collection of Physics Experiments, Department of Physics Education, Faculty of Mathematics and Physics, Charles University in Prague.

Concepts: 

Safety

General Safety

For Laboratory Work: Please refer to the ACS .  

For Demonstrations: Please refer to the ACS Division of Chemical Education .

Other Safety resources

: Recognize hazards; Assess the risks of hazards; Minimize the risks of hazards; Prepare for emergencies

 

NGSS

Students who demonstrate understanding can develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.

*More information about all DCI for HS-PS1 can be found at  and further resources at .

Summary:

Students who demonstrate understanding can develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.

Assessment Boundary:

Assessment does not include calculating the total bond energy changes during a chemical reaction from the bond energies of reactants and products.

Clarification:

Emphasis is on the idea that a chemical reaction is a system that affects the energy change. Examples of models could include molecular-level drawings and diagrams of reactions, graphs showing the relative energies of reactants and products, and representations showing energy is conserved.

Energy help students formulate an answer to the question, “How is energy transferred and conserved?” The Core Idea expressed in the Framework for PS3 is broken down into four sub-core ideas: Definitions of Energy, Conservation of Energy and Energy Transfer, the Relationship between Energy and Forces, and Energy in Chemical Process and Everyday Life. Energy is understood as quantitative property of a system that depends on the motion and interactions of matter and radiation within that system, and the total change of energy in any system is always equal to the total energy transferred into or out of the system. Students develop an understanding that energy at both the macroscopic and the atomic scale can be accounted for as either motions of particles or energy associated with the configuration (relative positions) of particles. In some cases, the energy associated with the configuration of particles can be thought of as stored in fields. Students also demonstrate their understanding of engineering principles when they design, build, and refine devices associated with the conversion of energy. The crosscutting concepts of cause and effect; systems and system models; energy and matter; and the influence of science, engineering, and technology on society and the natural world are further developed in the performance expectations associated with PS3. In these performance expectations, students are expected to demonstrate proficiency in developing and using models, planning and carry out investigations, using computational thinking and designing solutions; and to use these practices to demonstrate understanding of the core ideas.*

*More information about all DCI for HS-PS3 can be found at 

Summary:

Energy help students formulate an answer to the question, “How is energy transferred and conserved?” The Core Idea expressed in the Framework for PS3 is broken down into four sub-core ideas: Definitions of Energy, Conservation of Energy and Energy Transfer, the Relationship between Energy and Forces, and Energy in Chemical Process and Everyday Life. Energy is understood as quantitative property of a system that depends on the motion and interactions of matter and radiation within that system, and the total change of energy in any system is always equal to the total energy transferred into or out of the system. Students develop an understanding that energy at both the macroscopic and the atomic scale can be accounted for as either motions of particles or energy associated with the configuration (relative positions) of particles. In some cases, the energy associated with the configuration of particles can be thought of as stored in fields. Students also demonstrate their understanding of engineering principles when they design, build, and refine devices associated with the conversion of energy. The crosscutting concepts of cause and effect; systems and system models; energy and matter; and the influence of science, engineering, and technology on society and the natural world are further developed in the performance expectations associated with PS3. In these performance expectations, students are expected to demonstrate proficiency in developing and using models, planning and carry out investigations, using computational thinking and designing solutions; and to use these practices to demonstrate understanding of the core ideas

Assessment Boundary:
Clarification:

Students who demonstrate understanding can create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

*More information about all DCI for HS-PS3 can be found at 

Summary:

Students who demonstrate understanding can create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

Assessment Boundary:

Assessment is limited to basic algebraic expressions or computations; to systems of two or three components; and to thermal energy, kinetic energy, and/or the energies in gravitational, magnetic, or electric fields.

Clarification:

Emphasis is on explaining the meaning of mathematical expressions used in the model. 

Join the conversation.

All comments must abide by the ChemEd X Comment Policy, are subject to review, and may be edited. Please allow one business day for your comment to be posted, if it is accepted.

Comments 2

Renee Haugen | Tue, 01/21/2020 - 12:45

This is amazing, thank you! A couple of years ago I purchased two Seek thermal cameras, one for iPhone and one for Android with some ideas of what I wanted to do with it. It is great to visualize heat transfer, i.e. heat travels from warmer to colder and not vice versa. It leads us into discussion of specific heat of various materials. I use it in chemistry and also field biology courses. I'm still looking for more ideas for the field biology. I love the creative use of the camera for the greenhouse gases. That is a good one for both courses!

Ben Meacham's picture
Ben Meacham | Tue, 01/21/2020 - 20:41

Realizing the potential for its use across multiple disciplines is really the "carrot" that should allow for at least one of these cameras in every sci department.  Not totally sure if these ideas would be helpful for your field bio course, but I happened to stumble across Vernier's biology applications with the FLIR ONE camera (see below).  Maybe one of these might be helpful?