Photon Remote Temperature Sensor
Building this remote temperature sensor teaches practical, hands-on skills in hardware and software engineering. Beyond direct project-based learning, there are tons of ways to extend this project for classroom and other citizen science activities. Here are a few ways to use this system to teach fundamental scientific concepts.
What is Temperature?
This system measures temperature at a very specific, and known, location, which allows us to combine our direct observations with experimental data. Create your own experiment to change the temperature reading by changing the outside environment, keeping everything else the same.
For example, move the temperature sensor into direct sunlight, and gather data over a specific time interval, then move the temperature sensor back into the shade for the same amount of time. Analyze how the temperature reading changes and compare it to your own observations of outside temperature. Experiment with different ways to change the temperature reading. Be creative*, and see what tests your students think up!
* Avoid water contact unless you've thoroughly coated the electrical connections in epoxy or other waterproof adhesive.
Heat Capacity: Comparison of Temperature and Heat
Build the temperature sensor case to be air-tight, then use different material types and/or sizes of enclosures to analyze the difference between temperature and heat. Different materials have different heat capacities, or the amount of heat needed to raise the material's temperature by one degree. In other words, materials absorb and retain heat at varying rates. This helps us understand that heat is a form of energy, while temperature is a measure of that energy.
For each case, place sensor in direct sunlight and leave overnight. Determine how quickly the temperature sensor reading increases and decreases. A high heat capacity material will slowly increase and decrease in temperature, whereas a low heat capacity material will quickly heat up and cool off. Create plots of the temperature changes for various cases to determine what types of materials, and what sizes, retain heat the most. Find patterns between different material types and use those patterns to determine why certain materials have higher heat capacities.
Analysis of Data Trends: Long-Term vs. Short-Term
The difference between daily temperature and average temperature is a crucial concept in understanding climate change. It also provides a real-world application of the difference between long- and short-term trends. Fortunately, the data.sparkfun.com service makes this analysis simple and straightforward, the hardest part is waiting! It is also suggested to have a back-up battery if you live in a cloudy climate (like Seattle).
For this science lesson, gather data for a minimum of two (2) to three (3) months, ideally through a seasonal change. Download the data and find the average (mean) temperature by day, week, and month. Select a few 24-hour periods to plot temperature, and compare daily fluctuations with your calculated averages. See if you can use the temperature data to pinpoint the changing seasons!