Signal-to-Noise Ratio
The signal-to-noise ratio serves to characterize electronic components such as the UCI Universal Chromatography Interface or a UV or photodiode array detector. The lower the Noise is, the smaller the possible signal variations that can be recorded. As a general rule, the average of a signal should be at least twice (or, if possible, three times) the standard deviation of the signal value.
The signal-to-noise ratio of the Dionex UVD 340U Photodiode Array Detector is 1500 mAU / 0.005 mAU (254 nm, 8 nm, 1 s). Measurement of this technical specification is within a clearly defined scope. This includes the wavelength information (254 nm), the bandwidth, and the Step. The values can be realized only with an empty flow cell and a new lamp that has been adequately burned in (approximately 40 h). The maximum signal variation (in AU) is measured at maximum light radiation through the flow cell.
If establishing comparable specifications is not relevant, the signal-to-noise ratio can be improved by the following operations:
Selecting a low Sampling Rate
Using photodiode bunching (Bandwidth)
Selecting the Optimum Integration Path