467 / Clinical Chemistry I ASCP
review (youlazy)
Questions & Answers
,Which of the following lamps provides a continuous spectrum of
radiant energy in the visible, near IR, and near UV regions of the
spectrum?
A. Tungsten-filament
B. Hydrogen
C. Deuterium
D. Mercury vapor - CORRECT ANSWER-A most common light
source for photometry in the visible region. continuous spectrum
(360-800 nm). near IR and UV.
Hydrogen and Deuterium (200-375 nm)
Mercury vapor- not a continuous spectrum, emitting radiation at
specific wavelengths
Which of the following isolates light
within a narrow region of the spectrum?
A. Photomultiplier tube
B. Monochromator
C. Photovoltaic cell
D. Detector - CORRECT ANSWER-B Use for selecting a narrow
band wavelengths from a continuous spectrum. Three kinds
(prisms, filters, diffraction gratings.
,Which of the following is not descriptive of a photomultiplier
tube?
A. Emits electrons proportionally to
initial light absorbed
B. Must be shielded from stray light
C. Cannot be used with a chopper
D. Amplifies the initial signal received - CORRECT ANSWER-C
PMT- responds to the radiant energy light it absorbs by emitting
electrons in a proportional amount to the initial light absorbed.
Which of the following is false about
a photomultiplier tube?
A. Converts radiant energy (light)
to electrical energy (current)
B. Amplifies the current significantly
C. Has a very rapid response time
D. Is composed of an iron plate and
a layer of selenium - CORRECT ANSWER-D is part of a barrier
layer cell
PMT- 1. light to electricity
, 2. Amplification
5. Which type of photodetector employs a linear arrangement
that allows it to respond to a specific wavelength resulting in
complete UV/visible spectrum analysis?
A. Photomultiplier tube
B. Phototube
C. Barrier layer cell
D. Photodiode array - CORRECT ANSWER-D
256-2048 arranged in a linear fashion
Respond to a specific wavelength that results in a continuous
UV/ visible spectrum.
When performing spectrophotometer
quality assurance checks, what is the
holmium oxide glass filter used to assess?
A. Linearity
B. Stray light
C. Absorbance accuracy
D. Wavelength accuracy - CORRECT ANSWER-D