Metrohm 746 VA Trace Analyzer User Manual
Page 144
4.5 Basic method for DP polarography
746 VA Trace Analyzer / 747 VA Stand
4-59
•
If you do not want an automatic printout in the following determination,
you can either delete this line with the softkey
<Delete line>
or clear
the output destination
Printer
for the line with the <CLEAR> key.
•
Press the softkey
<Comment>
. The subpage of "DOCUMENTATION"
appears with the method comment describing, among other things, the
procedure used in the determination.
•
Finally press the <ESC> key to return to the main page of "DOCUMEN-
TATION".
4.5.4
Performing the determination
To perform the determination, the following steps are necessary:
1
Switch to dialog page "MONITORING"
•
Press the yellow <MONITORING> key. The dialog page "MONITORING"
whose header shows the loaded method
POL
appears.
2
Switch the program run mode to
determination
If the parameter
Run mode
is set to
calibration
, proceed as follows:
•
Use the cursor keys to select the field
Run mode
.
•
Press the space bar to enter the edit mode.
•
Press the softkey
<determ.>
and confirm this entry with the <ENTER>
key.
3
Entry of the sample volume
Enter the sample volume as follows:
•
Use the cursor keys to select the first field below the title
Sample
size/S0
.
•
Press the space bar to enter the edit mode.
•
Enter
10 mL
and confirm this entry with the <ENTER> key.
4
Start the determination
•
Press the red <START> key.
•
The status display in the header of the dialog page "MONITORING"
switches to
* BUSY *
, the start time of the measurement is entered un-
der
Determination
and the determination is given a standard name,
also formed from the start time. Further, during the measurement the
measurement window is superimposed which shows the current pro-
gram line being executed and the remaining line time.
•
Shortly after the start of the determination, the screen shows the prompt
to add 10 mL sample to the measuring vessel.
5
Addition of sample
•
Remove stopper 25
25 on 747 VA Stand and use a pipette to add 10 mL of
drinking water to the measuring vessel through the pipetting opening.
Press the <ENTER> key.
•
The screen shows the prompt to add 1 mL acetate buffer to the measur-
ing vessel.