Determination of the polymer composition of mid-twentieth century purses by Raman spectroscopy

Heritage Science

Table 3 Effects of laser power on the Raman spectral match quality and signal-to-noise ratio for CA

Laser power (%)^a	Correlation match quality (%)	Signal-to-noise ratio^b (1729 cm⁻¹ peak)
100	98.1	120
80	98.0	108
60	97.9	68
40	97.1	48
20	91.0	32
10	27.0	16

^aFull laser power (100%) is approximately 200 mW
^bSignal-to-noise ratio = \(\frac{{\overline{E}}}{s}\) where \(\overline{E}\) is the mean value of the peak height and s is the standard deviation of the noise measured along a flat portion of the baseline, 2300–2500 cm⁻¹. See Fig. 5