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Optimizing the detector
AZURA® Detector DAD 6.1L, DAD 2.1L, MWD 2.1L Instructions, V6700
The default data rate setting for the detectors is 1 Hz (see section „5.5
Default settings“ on page 31). The maximum data rate (digital signal)
is 100 Hz. Lower data rates store average data points. A 50 Hz data rate
averages 2 points. A 10 Hz data rate averages 10 points. The analog data
rate is fixed at 12.5 Hz.
The optimal data rate depend on your application. Too few points across
a peak (short data rate) decrease detail and compromise reproducibility.
Too many points (high data rate) introduce noise into the system and the
resulting files can become very large. Some general considerations are
lis ted below:
Each peak should be defined by 20–30 data points. For chromato-
grams with co-eluting peaks or low signal-to-noise ratios, 40–50 data
points per peak are recommended.
If all peaks are relatively wide, select a slower data rate.
If any peaks of interest are less than a few seconds, select a faster data
rate.
If the data rate is too slow, the start and end points of the peaks are not
accurately determined. If the data rate is too fast, data files may occupy
excessive disk space and post-run analyses may require more proces-
sing time.
Fig. 29:
Noise with different data rates
6.6 Integration time
The integration time influences the intensity of the signal and therefore
the sensitivity of the measurement. The larger the integration time, the
higher the intensity of the signal until the maximum sensor counts are
rea ched. The integration time is automatically calculated by the software
before the start of a measurement. The calculations are in relation to the
special range (see paragraph „6.4 Spectral range“ on page 38).
When a narrower spectral range is selected, the signal intensity will be
increased. This increase is limited, however, by the data rate.
Default data rate
Optimizing
the data rate
Signal level
