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3-21
IM AQ6373-01EN
Preparing for Measurement
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App
Index
Stray Light from the Monochromator
Selecting CHOP MODE
The instrument has a newly designed, high-performance monochromator. Depending
on the measurement conditions, stray light at a level 30 to 50 dB below the original
spectrum, as well as other stray light specific to the monochromator may occur in
wavelength areas 100 to 200 nm from the peak wavelength. If this stray light is likely
to have a severe impact on measurements, the sensitivity can be set to HIGH 1–3 and
CHOP MODE can be set to CHOP or SWITCH in order to reduce the effects of the stray
light.
Waveform with CHOP MODE OFF
CHOP MODE set to SWITCH
CHOP MODE Function List
CHOP
MODE
Function
Merit
Defect
OFF
Measurement according to the
stray light.
Stray light suppression ratio:
40 dB or more
Measurement time is rapid
even for high sensitivity
measurements.
Since the stray light is also
measured, the low level
component is not accurate
if the light source is of high
power.
SWITCH
Two sweeps per measurement
are performed. The first sweep
measures the stray light
component, and high dynamic
measurement is possible
through subtraction.
Stray light suppression ratio:
60 dB or more
measurement can be taken
with stray light removed.
If the measurement duration
is long, it is influenced by
temporal changes in the
measured light.
Selecting FIBER CORE SIZE
When LARGE is selected, the stray light increases.
Waveform with CORE SIZE SMALL
CORE SIZE set to LARGE
3.7 Important Points During Measurement