Owner's manual

7 How to ...?
757 VA Computrace – Software
148
13. Start the measurement by clicking the icon in the
MAIN
WINDOW
or the button in the
MONITORING
window.
14. Enter the
Sample ID
(used as part of the determination file
name) in the
PLACE SAMPLE
window and click
<OK>
.
15. Each time a solution exchange is required in the
BATCH SO-
LUTION EXCHANGE
window, replace the measuring solution
by the next spiked sample solution.
Use automatic standard addition
In the automatic standard addition, a known amount of the ana-
lyte is added once or several times to the sample using 665 or
765 Dosimats. Proceed as follows:
1. Install Dosimats to the 757 VA Computrace Stand (see How to
install Dosimats).
2. Click on or
MAIN WINDOW / Mode / Determination
.
3. Click on or
MAIN WINDOW / Window / Working method
specification
to open the
WORKING METHOD SPECIFICATIONS
window.
4. Load the desired method into the
WORKING METHOD SPECIFI-
CATIONS
window (see How to load a method).
5. Select
Standard addition
in the
Calibration
field of the
WORKING
METHOD SPECIFICATIONS
window.
6. Select
Automatic
in the
Addition
field of the
WORKING METHOD
SPECIFICATIONS
window.
7. Click to open the
DOSIMATS
window.
8. Check the Dosimats which are should be used for standard
addition in the
Dosimat used
field (see Dosimats, section 5.2).
9. Close the
DOSIMATS
window by clicking
<OK>
.
10. Click to open the
EDIT WORKING METHOD PA-
RAMETERS
window.
11. Select the
Determination
tab (see section 5.2) and enter
Sam-
ple identifier
,
Sample amount
,
Cell volume
, and the number of
standard additions in the
No. of additions
field.
12. Select the
Substances
tab (see section 5.2) and make sure
that for each substance entered in the table the number of the
single or mixed standard addition solution, its concentration
and its volume is defined. The
No.
of the standard solution
must be identical to the number of the Dosimat used for
automatic addition of this solution.