PerkinElmer 200A Series, User Manual

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Maintenance . 127
NOTE:
In measurement with the emission spectrum bandwidth set at WIDE (30 nm), the peak emission
wavelength is shifted toward the shorter wavelength side from 397 nm. Due to the WIDE setting,
the spectrum bandwidth widens for the scattered light of excitation beam and the Ramen line of
water. Therefore, the wavelength of the scattered light (for more details see chapter 3 System
Description).
5. Noise Calculation
Calculate the noise level on the chart by the method given in Fig. 6-3. The noise level in the case
of using the recorder is obtained from the noise width (in mm) as follows.
X: ATT setting of data processor used in measurement
6. S/N Ratio Calculation for Raman Spectrum of Water
Perform calculation according to the S and N obtained in the preceding subsections (3) and (5).
a. Excitation spectrum bandwidth: 15 nm
b. Emission spectrum bandwidth: 15 nm
Fig. 6-3 Noise Calculation (extracted from JAIMAS 0005-1984)
NOTE:
The Raman spectrum of water and the noise level may be affected by the purity of the water used
and/or the presence of air bubbles.