How to Measure the Red in the Color Spectrum
- 1). Identify the peak wavelength of your band pass filter. A band pass filter allows only a narrow range of wavelengths to get through. To make a precise measurement, you must know exactly what range is going through. Precision filters will usually be supplied with a curve that shows the peak and the range of wavelengths that make it through.
- 2
Transmission filters let only a narrow range of wavelengths through.Zedcor Wholly Owned/PhotoObjects.net/Getty Images
Determine the throughput of your filter. To make a precise measurement, you need to know not only what wavelengths get through your filter, but how much of those wavelengths get through. Precision filters will provide that data. For less accurate filters, you can record a reading with one filter, then add another filter and record --- the percent difference will give you an idea how much of your peak wavelength is getting through. - 3). Put the detector in the light and record a reading.
- 4). Place the red band pass filter in front of the detector and record again. Divide that reading by the percent transmission determined in Step 2.
- 5). Divide the red light measurement by the total light measurement. That is the amount of red in the color spectrum.
