spectrum (redirected from emission spectrum)

spectrum /spec·trum/ (spek´trum) pl. spec´tra   [L.]

1. a charted band of wavelengths of electromagnetic radiation obtained by refraction or diffraction.

2. by extension, a measurable range of activity, as the range of bacteria affected by an antibiotic (antibacterial s.) or the complete range of manifestations of a disease.

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absorption spectrum  that afforded by light which has passed through various gaseous media, each gas absorbing those rays of which its own spectrum is composed.

broad-spectrum  effective against a wide range of microorganisms; said of an antibiotic.

electromagnetic spectrum  the range of electromagnetic energy from cosmic rays to electric waves, including gamma, x- and ultraviolet rays, visible light, infrared waves, and radio waves.

fortification spectrum  a form of migraine aura characterized by scintillating or zigzag bands of colored light forming the edge of an area of teichopsia.

visible spectrum  that portion of the range of wavelengths of electromagnetic vibrations (from 770 to 390 nm) which is capable of stimulating specialized sense organs and is perceptible as light.

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spec·trum (spktrm)

n. pl. spec·trums or spec·tra (-tr)

1. The distribution of a characteristic of a physical system or phenomenon, especially the distribution of energy emitted by a radiant source arranged in order of wavelengths.

2. The color image presented when white light is resolved into its constituent colors: red, orange, yellow, green, blue, indigo, violet.

3. The plot of intensity as opposed to wavelength of light emitted or absorbed by a substance, usually characteristic of the substance and used in qualitative and quantitative analysis.

4. The distribution of atomic or subatomic particles in a system, as in a magnetically resolved molecular beam, arranged in order of masses.

5. The group of pathogenic organisms against which an antibiotic or other antibacterial agent is effective.

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spectrum

pl. spectra, spectrums [L.]

1. the series of images resulting from the refraction of electromagnetic radiation (e.g. light, x-rays) and their arrangement according to frequency or wavelength.

2. range of activity, as of an antibiotic, or of manifestations, as of a disease.

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absorption spectrum

one obtained by passing radiation with a continuous spectrum through a selectively absorbing medium.

antibacterial spectrum

the range of bacteria susceptible to a particular antimicrobial or class of antimicrobials.

broad-spectrum

effective against a wide range of microorganisms.

visible spectrum

that portion of the range of wavelengths of electromagnetic vibrations (from 770 to 390 nanometers) which is capable of stimulating specialized sense organs and is perceptible as light.