Knauer K-2600 Handbuch Seite 16

16
Selecting wavelength(s)
Position the cursor on one of the two wavelength fields and select the
wavelength by entering the desired values with the numeric keys. If you
want to use one single wavelength, enter a Zero in the unused fields.
Entering zero deactivates the respective wavelength. If you use both
wavelengths, the polychromator moves between the positions
corresponding to the selected wavelengths. This movement is
performed with a frequency of 10 Hz that cannot be changed and. You
can hear the motor of the polychromator as a high frequency tone.
A cut-off filter for suppressing secondary grating orders is activated
automatically if one or both wavelength(s) exceed 381 nm and a
deuterium lamp is installed. The use of the filter is displayed by a
+
superscripted , as shown in Fig. 13.
Output options: The Output of absorption signals can be configured.
Move the cursor to the signal fields. Choose between different options
by pressing any numeric key. Options are:
−
Signal inversion indicated by a little superimposed minus sign.
Two different ratio plots are available:
−
Wavelength (1) divided through wavelength (2) and
−
vice versa.
Ratio plots are indicated by symbol 1/2 and respectively 2/1 at the
decimal point of the absorption value Fig. 14.
Fig. 14 Inversion of the signal and ratio plots: Set indicated output
options
Ratio plots contain information on peak purity. It is calculated by dividing
the intensity values at two different wavelengths. It is possible to
measure the absorption at one wavelength and to monitor
simultaneously the ratio of absorption between this wavelength and
another one. Ratio plots can be accessed at either analog out
connector or via digital data acquisition.
The scaling of the analog outputs can be adjusted to different values of
Absorption Units or to different voltage values. For detailes see section
„ANALOG OUT FULL SCALE:" on page 12 in section „The SETUP
Menu".
EVENTS — The EVENT outputs on the rear side of the instrument
provide time programmed signals to other instruments. All features,
together with that of the remote control socket, is described in chapter
„Connecting other Instruments to the K–2600 UV detector" on page 24.
When working without a time program, using events enables fraction
collection, as described in section "FRACTION" on page 13 in chapter
„The SETUP Menu".
Operating the Photometer