Teledyne UA-6, Инструкция по установке и эксплуатации

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UA-6 Detector
Section 3 Operation
3-11
6. Apply a back pressure on the flow cell by using a 100 psig
back pressure regulator (available from Teledyne Isco, part
number 209-9012-22), a long piece of small bore tubing, or
some other device on the outlet side of the flow cell. Keep
the column-to-flow cell tubing length as short as possible.
This is especially true for exclusion chromatography (gel
filtration) because of its higher initial pressure.
Note
A one meter length of 0.005 inch ID stainless steel tubing will
provide a back pressure of approximately 75 psig at a flow rate
of 0.25 ml per minute, 135 psig at a flow rate of 0.5 ml per min-
ute, and 275 psig at a flow rate of 1.0 ml per minute.
7. Limit the vertical fall of the outlet tubing as much as possi-
ble to reduce siphoning action.
3.9 Noise Filter
The UA-6 includes a built-in noise filter with RISE TIME set-
tings of 0.5, 1.5 and 5.0 seconds. (RISE TIME is a response speed
measurement defined as the time required to make a 10% to 90%
pen deflection.) This filter can be used to reduce the noise level
on the recorder trace. It is especially useful for reducing or elimi-
nating flow noise caused by pulsatile pumps or noisy solvents
(see Figure 3-7). The figure demonstrates the ability of the noise
filter to reduce baseline noise at 0.002 AUFS.
The filter used is an active Bessel filter. Bessel filters are advan-
tageous because they merely delay rather than distort the shape
of peaks. This delay causes some increase in the response time of
a peak and reduces the peak height of very short duration peaks,
but the peak areas remain constant.
Figure 3-7 Effect of Noise Filter on Baseline Noise
In many low pressure LC applications, the 1.5 and 5.0 second set-
tings can be used to reduce baseline noise without any negative
effect to the chromatogram.
Note
Use of the 1.5 and 5.0 seconds rise time settings is highly rec-
ommended for peak separation in low pressure LC. These set-