Hach-Lange DR 2800 eco - Manual (Page 74)

72
Advanced Operations
3. Press the "+" symbol again (see arrow) and enter the next
standard concentration. Repeat this sequence until all standard
conentrations (maximum of 24 solutions) have been entered.
Activate the line with the appropriate concentration and insert
the cuvette with the corresponding standard solution.
4. Place the zero solution in the cell compartment. Press Zero.
5. Place the first standard solution in the cell compartment. Press
Read.
Place the second standard solution in the cell compartment.
Press Read.
Repeat this sequence until all the standard solutions have been
measured (maximum of 24 solutions).
The entered and measured data are displayed in the table.
Note: If you want to delete a standard concentration, press the appropriate
line and press the Delete icon.
6. The timer icon shown in the display helps to ensure, when
necessary, that the steps of an analysis are correctly timed
(e.g. reaction times, wait times, etc., can be exactly specified).
When the specified time has elapsed, an acoustic signal is
emitted. The use of the timer has no influence on the
measurement program.
7. When the data have all been entered and the measurements
have all been carried out, you can display the curve that results
from plotting the entered data by pressing Graph.
8. The linear curve corresponds to the standard setting. If you
press Next Curve the polynomial 2nd order curve is displayed,
and if you press Next Curve again, the polynomial 3rd order
curve is displayed.
9. Press Force 0 to change the setting from Off to On. The curve
then passes through the origin of the coordinate system.
Note: This may have an adverse effect on the correlation coefficient
(r
2 ).
10. Press Table to display the table again.
11. When the table has been completed and the curve type has
been chosen, press Done.