| Table 1. Apparent Specific Absorbances, ea, kg•g-1•cm-1
|
Nominal
| Wavelength and (Bandpass)
|
Mass Fraction
| nm
|
g•kg-1
| 235.0(1.2)
| 257.0(0.8)
| 313.0(0.8)
| 345.0(0.8)a
| 350.0(0.8)
| Uncertaintyb
|
0.020
| 12.260
| 14.262
| 4.805
| 10.604
| 10.672
| ± 0.034
|
0.040
| 12.304
| 14.318
| 4.811
| 10.603
| 10.682
| ± 0.020c
|
0.060
| 12.347
| 14.374
| 4.816
| 10.602
| 10.692
| ± 0.020c
|
0.080
| 12.390
| 14.430
| 4.821
| 10.601
| 10.701
| ± 0.020c
|
0.100
| 12.434
| 14.486
| 4.827
| 10.600
| 10.711
| ± 0.020c
|
Nominal
| Wavelength and (Bandpass)
|
|
|
Mass Fraction
| nm
|
|
|
g•kg-1
| 235.0(1.6)d 257.0(1.6)d 313.0(1.6)d 345.0(1.6)d
| 350.0(1.6)d
| Uncertaintyb
|
0.120e
| 12.480 14.541 4.835 10.600
| 10.722
| ± 0.04f
|
0.140e
| 12.524 14.605 4.840 10.599
| 10.731
| ± 0.04f
|
0.160e
| 12.567 14.658 4.846 10.599
| 10.742
| ± 0.04f
|
0.180e
| 12.609 14.711 4.851 10.598
| 10.751
| ± 0.04f
|
0.200e
| 12.649 14.763 4.856 10.597
| 10.759
| ± 0.04f
|
a Wavelength 345.0 nm is near one of the two isosbestic points in HCrO4 -/Cr2O7 2-spectra. Because it is on the slope of the composite spectrum, reproduction of the ea values is dependent on wavelength accuracy. Measurements at this wavelength should be made only for verification of the linearity of the absorbance scale.
|
b ea values are not corrected for the effects of internal multiple reflections within the cuvette, nor have the weights been corrected to vacuum. With these two exceptions, each uncertainty given is the 95 % confidence interval of the mean and includes all known systematic errors.
|
c At wavelength 313.0 nm, the uncertainty is reduced to ± 0.010 kg·g-1·cm-1 .
|
d The increase in spectral bandpass is necessary to obtain an adequate signal. Expected changes in specific absorbance due to this increase do not exceed 1 part in 1,000.
|
e ea values are given to the third decimal place to preserve the smooth variation of the data with concentration, although the uncertainties are in the second decimal place.f At wavelength 313.0 nm, the uncertainty is reduced to ± 0.020 kg·g-1·cm-1 .
|