Hach DR/820 Instrument Manual page 37

SECTION 4,
continued
10. Press . Four horizontal lines (denoting numeric entry)
ENTER
will be displayed.
11. Enter the standard's concentration, using the numeric entry
keys (the # icon will be illuminated on the display).
Note: Press the CE key to correct errors.
12. Press the
ENTER
Note: A beep means that the concentration is a duplicate of a previous
standard or the concentration is too high for the selected resolution.
Repeat step step 11 with a different concentration and continue.
13. Press the down
ARROW
by the number of the standard.
14. The colorimeter requires one zero be entered in this
procedure; the
ZERO
portion of the display. Place a blank into the cell holder and
press the key. Four horizontal lines will appear, then
ZERO
disappear, across the display. The
appear in the lower portion of the display.
Note: If necessary, the colorimeter can be re-zeroed. The most recently
entered zero will be used for subsequent readings.
15. Prepare the standards using the same reagents and procedure
used to test samples.
16. Place the prepared standard into the cell holder.
17. Press the key. An absorbance value will be displayed.
READ
Note: Or, press the ENTER key to input an absorbance value or change
the value read by the instrument. Use the numeric keys to enter the
value then press the ENTER key.
Note: A beep indicates that the absorbance is a duplicate of a previously
entered standard or that it falls between two previous standards.
Repeat steps step 15 through 17. with the correct standard, or press
the up ARROW key and repeat steps 9. through 17. with a correct,
prepared standard and blank.
18. Press the down
ARROW
19. Repeat step 9 through step 18 for all remaining standards.
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key. The concentration will be displayed.
key. will be displayed followed
ABS
action icon will appear in the lower
READ
key to advance to the next standard.
action icon will