horiba FluoroMax-3, Руководство по эксплуатации

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FluoroMax-3 v. 3.1 (3 Mar 2006) System Operation
3-15
Results
The measurements provided the following data:
S
peak
peak signal at 397 nm 501 500 cps
S
background
background noise at 450 nm 10 500 cps
N
p–p
Peak-to-peak noise of background at 450 nm* 223 c
*Measured with a separate kinetic scan
N
p–p
gives an rms noise of the background signal of
N
rms background
,
.
=
=
223
5
44 6
c
The HORIBA Jobin Yvon method gives a water-Raman
S
/
N
of
S
N
S S
S
peak background
background
=
−
=
−
=
501500 10 500
10 500
4790
The other method similarly gives a water-Raman
S
/
N
of
S
N
S S
N
peak background
rms background
=
−
=
−
=
,
.
501500 10 500
44 6
11000
HORIBA Jobin Yvon feels that the first method is correct although it gives a lower
S
/
N
.
The second method only takes into account the detector noise and the shot noise of the
electronics. By using the background total intensity as a measure of noise, the HORIBA
Jobin Yvon method is more representative of a real “live” experiment where noise is
also influenced by factors like the quality of the optics and scattered light in the system.
These additional factors influence the ability to measure a very low signal from a sam-
ple and should not be ignored.