Turn Your Phone Into a Spectrometer — For Free!

Our world is filled with different light sources: fluorescent office lights, sodium street lamps, and bright neon lights to name a few. Now you can see all of the emission spectra of these light sources with our new iPhone app: SpectraSnapp. Did I mention that it's free?

Remember those flame tests from high school chemistry class? You would burn a specific element — such as copper or sodium — and each element would burn with a different color. For instance, sodium burns with an intense yellow flame while lithium will burn red.

These characteristic colors emerge because every element or chemical compound has its own emission spectrum. When an atom's electrons are excited, it will emit photons of specific wavelengths. Atoms emit photons of various energies when electrons are excited from one energy level to another.

The magnitude of the energy jump for the electrons determines the energy — and subsequent color — of the emitted photons. Using an instrument known as a spectrometer, physicists can see the unique emission lines for an element or compound. With SpectraSnapp, now you can too!

APS Outreach Specialist James Roche shows off SpectraSnapp.
Image Credit: Mike Lucibella/APS.

SpectraSnapp makes use of the iPhone's camera to image spectra of any light source. You'll need to make a few quick adaptations first, however.

As you can see in the image above, you'll have to create a makeshift spectrometer to append to your phone's camera. The app has the full details on how to build your device which requires just a few items:

• A diffraction grating
• Black construction paper
• And electrical tape (black works best)

After you've made your spectrometer, just point your camera at any nearby light sources to reveal the underlying emission lines. Once you snap your picture, it's time for analysis.

The app lets you do some basic photo editing to perfect your spectrum sample. You can crop, rotate, change the brightness, and alter the contrast for your spectrum image.

Next, you can compare your spectrum to our library of spectra for a number of other light sources. The library includes spectra for many gas discharges and common light sources. By comparing your spectra, you can start to see how your sample generates its light. Maybe your sample looks like a sodium discharge, or maybe it looks more like the red and orange heavy emission of neon.

An example spectrum of a white CFL bulb taken with the app.
Image Credit: Brian Jacobsmeyer

Finally, you can of course share your spectra through Facebook, Twitter or Instagram. All of your photos will be stored in your phone's camera roll.

For now, the app is only available for iPhones and iPads, but we hope to branch out to Android devices in the future. Make sure to let us know what you think in the comments.

To download the app, simply search for "SpectraSnapp" in the app store on your device. Otherwise, you can follow the download link below.

Download and More Links

Download the App (iTunes Store)

APS News Article on SpectraSnapp