Knauer Smartline 2300 Benutzerhandbuch Seite 16

Operating the RI Detector 2300/2400
I +I Menu
1 2
on line:
AUTOZERO:
fixed ->1:
limit:
AUTOZERO and Repositioning the Zero Plate
CALIBRATE Menu
In this menu the values I
displayed. Best measurement results are achieved if both I
close to 0.5, which will result in I
Furthermore, a zeroplate adjustment can be activated by selecting the
function ZP.
I + I on line
1 2
♦ limit: 80 %
In menu I + I the following items can be selected:
1 2
I + I is continuously calculated for every current data point.
1 2
Thus it is ensured that fluctuating absorption components
have no influence on the measurement value. The noise
component in the measurement signal increases slightly.
I + I will be kept constant during the entire measurement.
1 2
The current intensity of the sum is recalculated after
activation of AUTOZERO and saved.
For the entire duration of measurement I
1. This mode corresponds to the detection method of the
former KNAUER RI 98.00 types.
By selecting the item limit and setting a certain percentage
with the ▲ or ▼ key a limit of light intensity is set. If the
detected light intensity falls below this limit, it will be
displayed in the main menu. Otherwise no light intensity is
displayed.
Best measurement results are obtained if the sum of I
(corresponding to a detected light intensity of 100%) and if the difference
I – I is close to zero. The minimum detected light intensity (I
1 2
should always exceed 80%. The intensity values I
the INTENSITY menu.
The electronic function Autozero serves for correction of a base line
offset due to drift that may be caused by thermal or solvent fluctuations.
Large deviations from the optimum values can be corrected with a zero
plate adjustment. First it should be checked if deviations in I
caused by an air bubble in the cell. This can be recognized by a very
small light intensity I
1
difference in I < I . An air bubble in the cell can be removed by rinsing
2 1
with solvent and by using the Flush function to flush the reference cell.
During error-free operation, the zero plate adjustment can be activated by
selecting the function ZP in the SIGNAL menu or by pressing the
AUTOZERO key for more than 3 s. If a certain preset difference between
I and I is exceeded a zero plate adjustment is performed automatically.
1 2
CALIBRATE 2.195e-3 mRIU
♦ coarse
In this menu the calibration constant c which is used for signal value
calculation (according to Formula 2 on page 5) can be selected. Available
settings are in the range of 0.125 up to 128.0 x10
setting, place the cursor on the position coarse or fine using the ► or ◄
key. Now you can select the desired value by means of the ▲ or ▼ key.
+ I and I – I , calculated from I
1 2 1 2
+ I ~ 1.0 and I
1 2
+ I (displayed in the main menu) or by a big
2
fine
and I , are
1 2
and I are
1 2
- I ~ 0.
1 2
+ I is defined as
1 2
+ I is close to 1
1 2
+ I
1
and I are displayed in
1 2
and I are
1 2
–3
. For changing the
15
)
2