Effect of Resolution and Throughput on SNR

For measurements made under the variable throughput criterion, a greater penalty is paid for increasing the resolution. In this case not only is Av halved, but so is 0 (see Eq. 7.11). Thus, the SNR is reduced by a factor of 4 (i.e., the noise level of the 100% line is quadrupled). In this case, the measurement time must be increased by a factor of 16 to regain the original SNR. 

The discussion above considers only the effect of changing the resolution on the noise level of the 100% line the effect of changing the resolution on the intensity of spectral features should also be considered. If Av is much narrower than the EWHH of the features in the spectrum, changing the resolution has a minimal effect on the intensity of these features. This would be the case for many condensed-phase 

---