The goal of this kickstarter is to raise $8,000 to fund the manufacture of an affordable scientific colorimeter kit for educators, students and DIY scientists. The colorimeter kit is an open source hardware project. Colorimeter design files and software are all available at https://bitbucket.org/iorodeo/colorimeter/.
What is a colorimeter ?
Colorimeters are analytical devices commonly used in science labs to measure the concentration of a solution from its light absorbing properties. Colorimeters are extremely useful and flexible lab instruments for a wide range of science education labs. Some examples of how the colorimeter can be used for are listed below.
- Investigate Beers Law - Use food dye or other colored solution to investigate the relationship between concentration and absorbance;
- Water quality - measure several water parameters such as turbidity, pH, water hardness, phosphate content and more;
- Population growth - measure the absorbance of a microbial culture over time to follow population growth;
- Enzyme kinetics - measure the activity of an enzyme over time and different environmental parameters (temp, pH, inhibitors);
- Nitrogen cycle - quantify the amount of ammonia, nitrite and nitrate in a newly established aquarium.
and much more .....
We purposefully designed the educational colorimeter as a kit rather than a pre-assembled instrument. The electronics are already assembled so no soldering is required. Assembly takes approximately 20-40 mins and so the build can be incorporated into a classroom activity. Step-by-step assembly instructions are posted on Instructables and in the colorimeter User Manual. Each colorimeter kit ships in a reusable tub for safe storage of kit parts in the classroom.
How it works
An RGB LED illuminates the sample in a cuvette with one of three different wavelengths of light: 625 nm (red), 528 nm (true green) and 470 nm (blue). A slit in the colorimeter allows light to pass through the sample to the light sensor. Absorbance of the sample is determined by comparing the intensity of incident light to the intensity of light after it has passed through the sample using the following equation:
Open source software - data collection and analysis
We have developed a suite of open source software tools to use with the colorimeter. These can be used to 1) collect transmission and absorbance data, 2) generate a plot of absorbance versus concentration and 3) calculate the concentration of a solution. The colorimeter software in this project includes several calibrated solutions with plans to extend the list of solutions if this Kickstarter is successful. The current list of calibrated solutions can be found here. Software for the basic program is available now. The additional features (plotting and absorbance measurements) will be available by July 2012.
To get you started working with the colorimeter we are also developing several introductory colorimetry labs. These can be found in the colorimeter User Manual and will be updated in the upcoming weeks and months. Some sample data from Lab 2 (Beers Law) is shown below. Materials for completing this lab (food dyes and 500 mL volumetric flasks) are included in the educational level rewards.
For more information on the educational colorimeter kit, visit the project website at www.iorodeo.com/colorimeter.
- (36 days)