In terms of Investigating the spectrum of a light source wha

In terms of Investigating the spectrum of a light source, what characteristics of a detector would aid in its ability to record a true spectrum of a light source?

Solution

When coupled with lighting, the term “full spectrum” implies that a light source offers even, uninterrupted spectral energy distribution (SED) (also calledspectral power distribution [SPD]) without the peaks and valleys associated with most discharge light sources (such as fluorescents, metal halides, etc.).

The Lighting Research Center defines “full-spectrum” as an equal-energy lamp (a lamp that provides equal energy in all visible wavelengths), according to Peter Boyce, professor emeritus at the Lighting Research Center. He points out: “There is also an operational definition which says that a full-spectrum lamp has some energy in all visible wavelengths, has a correlated color temperature of at least 5000K, and some UV emission.”

Some maintain that UV radiation is an essential part of full-spectrum lighting; but full-spectrum lamps that reduce radiation in a small part of the visible spectrum (in an effort to improve visibility) have emerged, and these products also have the “full-spectrum” label.

According to Brian Liebel of AfterImage + Space (principal investigator for the U.S. Department of Energy in terms of spectrally enhanced lighting, and a research leader on increased brightness and visual-acuity benefits of higher color-temperature lighting), the technically correct definition for full-spectrum lighting is “any light source that contains lighting energy throughout the visible spectrum.” Liebel also shares a second definition that describes full-spectrum lighting as a term used by some manufacturers that claim their products provide a more even distribution of lighting throughout the visible spectrum, similar to the way light energy is distributed in daylight.

What benefits are claimed for full-spectrum light sources?

A fluorescent or incandescent lamp claimed to be full-spectrum can cost several times as much as one with a nearly identical spectral power distribution (SPD) that is not identified as full-spectrum. What benefits does a consumer get for that extra money? NLPIP reviewed the promotional claims for full-spectrum light sources from manufacturer and retailer web sites, and found a diversity of claimed benefits, including: