Part A shows how limited the range of the Spectronic 20 spectrometer is. It did not measure

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Part A shows how limited the range of the Spectronic 20 spectrometer is. It did not measure transmittances below 400 nm or above 575 nm. This means the light source emitted those wavelengths of light so weakly they were not detected by the instrument. Figure 3 plots the relative overall response of the Spectronic 20, the relative response of a phototube, and the relative lamp intensities as a function of wavelength. The Spectronic 20 response curve shows a maximum relative response at 512 nm with a transmittance of 88.3%. The phototube response curve shows a maximum relative response at 400 nm with a transmittance of 100%. This means the light source used in Part A emitted green light stronger than any other wavelengths and the phototube…show more content…
The Ocean Optics does not have this ability and fluctuations that deviate from the accepted value are observed as shown by its residuals plot. The r2 value (see table 12 in Appendix A and table 13 in Appendix B) shows that the data are more linear for the Cary 60 instrument (r2 = 1.00) than for the Ocean Optics instrument (r2 = 0.994). The absorbances for the Cary 60 were more accurate than the absorbances for the Ocean Optics when compared against accepted absorbance values (Appendix C) for the absorbance accuracy and linearity portion of the experiment (tables 2 and 3). These differences can be attributed to stray light and background corrections. Because the Ocean Optics sample holder is exposed to outside light, it is more prone to scattered light error, which inflates the absorbance expected. The Cary 60 does not suffer from this issue because it is in a dark environment. Also, as previously discussed, the Cary 60 corrects for background whereas the Ocean Optics instrument does not. The calculated percent stray light for the Cary 60 and Ocean Optics measurements were 0.09% and 5.26%, respectively. The reason why these values were so different is explained by the environment in which the measurements were taken. The Cary 60 analyzed

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