Building a Low-Cost Spectrometer for the Classroom
Spectroscopy is one of the most powerful tools in science—it reveals the hidden fingerprints of light. But commercial spectrometers are often too expensive for schools to buy in class sets. The good news is that with a little creativity, it’s possible to build a low-cost spectrometer that still delivers useful results for teaching.
How It Works
A spectrometer splits light into its component wavelengths. By examining the spectrum, students can learn about:
-
Absorption and emission lines
-
Energy levels in atoms
-
Practical applications such as analysing stars, flames, or solutions
DIY Classroom Approach
To keep costs low, we can use simple, readily available components:
-
A cardboard or 3D-printed box to act as the housing
-
A narrow slit cut into foil or plastic to admit light
-
A diffraction grating or even a recycled DVD piece to split the light
-
A smartphone or webcam to record the spectrum
A more Upmarket approach using Lego
Benefits for Teaching
-
Hands-on learning: students see how scientific instruments are built and used
-
Affordable: multiple groups can each build one for less than the cost of a single commercial unit
-
Engaging: watching a rainbow spread across a screen never loses its appeal
-
Scalable: advanced students can calibrate the spectrum and measure wavelength peaks
The Takeaway
A low-cost spectrometer won’t rival professional kit, but it will give students an authentic, practical experience of spectroscopy. Building one gives the students some much better ideas on how these machines work. It’s proof that powerful science can be explored without a big budget.
