Hach DR 2800, Руководство пользователя, Страница: 59 / 96

59
Advanced Operations
7. Press the keys to enter the standard addition volumes. Use the
alphanumeric keypad to enter the new data and press
OK
.
8. A table of the reading is displayed.
• The first column shows the standard addition volume.
0 mL stands for a sample containing no added standard.
• The second column shows the reading of the samples with
and without added standard.
• The third column shows the detection rate of the added
standard.
• The black highlighted line is active.
9. The reading of the sample in the instrument, without added
standard, is automatically shown under 0 mL.
10. Prepare the standard addition solution as described in
the procedure.
11. Use the arrow keys to select the first standard addition volume
in the table and place the cell with the corresponding volume of
added standard in the cell compartment. Press
READ
.
Repeat the procedure from step 9 with all the other standard
addition solutions.
12. After all the standard addition solutions have been measured,
press
GRAPH
.
The regression line through the standard addition data points
is displayed.
The correlation coefficient r
2
indicates how close the data
points are to the line.
If the correlation coefficient = 1, the curve is linear.
The concentration shown above the curve is the estimated
concentration of the sample without the added standard.
Note: Press
TABLE
to display all the data in the table again.
13. Press
IDEAL LINE
to display the relationship between the
added standard solutions and the ideal line (detection rate
100%).