A spectrometer shines a light on a sample and
measures how much light is absorbed at a specific
wavelength. Knowing how much light is absorbed
can help scientists identify the substances in
a given sample, since each substance absorbs a
different amount of light at different wavelengths.
Spectrophotometers usually have a photomultiplier
tube that amplifies the signal for accurate measurement.
spectrometer shines a light on a sample
and measures how much light is absorbed
at a specific wavelength.
is how it works: first, a bright light source
is used to create light of a known wavelength
and intensity. The light passes through a monochromator,
which filters out all except a narrow band of
wavelengths (or colors) which will be used to
illuminate the sample. This narrow band of light
is passed through the sample material where some
is absorbed. The remaining light that passes through
the sample strikes the light-sensitive detector.
The detector generates an electrical signal in
proportion to the light intensity. The electrical
signal is amplified and read out on a meter or