Hach-Lange DR 2800 eco - Manual (Page 89)

87
Advanced Operations
7. Press the keys to enter the standard addition volumes. Use the
alphanumeric keypad to enter the new data. Confirm your input
by pressing OK.
Description of the table of readings
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.
Note: The black highlighted line is active.
8. The reading of the sample in the instrument, without added
standard, is automatically shown under 0 ml.
9. Prepare the standard addition solution as described in the
procedure.
10. Use the arrow keys to select the first standard addition volume
in the table and place the cuvette with the corresponding
volume of added standard in the cell compartment.
Press Read.
Repeat the procedure from point 8 with all the other standard
addition solutions.
11. 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: In the curve menu, the name on the Curve key switches to
Table. Press Table to display all the data in the table again.