AZURA® Detector RID 2.1L / RID 2.1L HighFlow Instructions V6750
Product information 29
It is recommended to set the time constant and data rate in relation to
peak width.
Peak width [min]
Time constant [s]
Data rate [Hz]
< 0.003
0.01
100
> 0.007
0.02
50
> 0.017
0.05
20
> 0.033
0.1
10
>0.067
0.2
5
>0.167
0.5
2
> 0.333
1
1
The data rate (or sampling rate) is the number of data points per second
(Hz) at which the detector transmits data to the computer. 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 20 Hz.
The default values are listed in a separate section (see 7.2 on page 27).
The optimal data rate depends 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
listed 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 shown 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 process-
ing time.
7.2.5 LED power factor
The LED power factor can be adjusted in order to regulate detector sen-
sitivity. Light source durability is also affected by changes to this param-
eter. By increasing or decreasing this factor, the total linear range of the
device is decreased. This setting can be adjusted in your software under
Advanced Settings.
The default values are listed in a separate section (see 7.2 on page 27).
After changing the LED power factor, the electric current to the light
source is altered and consequently the total sum of counts for both
diodes is adjusted. By increasing the LED power factor (e.g. from 1 to
1.8), it is possible to increase sensitivity due to decreased signal noise.
The upper limit is a total sum of 2 million counts. In the same way, it is
possible to decrease the sensitivity by decreasing the LED power factor
(e.g. from 1 to 0.5).
Data rate
Optimizing the data rate
Sensitivity
