Ph, Colorimetric Ph Determination Using Phenol Red - Hach DR/850 Procedures Manual

pH
(6.5 to 8.5 pH units)
Colorimetric pH Determination Using Phenol Red
1.
Enter the stored
program number for the
pH method.
Press:
PRGM
The display will show:
PRGM ?
5.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
6.0 PH
2.
Press:
75 ENTER
The display will show
PH and the ZERO icon.
6.
Fill another cell with
10 mL of sample.
Note: Sample temperature
must be 21-29 °C.
3.
Fill a sample cell
with 10 mL of sample
(the blank).
7.
Using a disposable
dropper, add 1 mL of
Phenol Red Indicator
Solution to the cell (the
prepared sample). Cap
the sample cell and
invert twice to mix.
337
Method 10076
For water and wastewater
4.
Place the blank in the
cell holder. Tightly
cover the sample cell
with the instrument cap.
8.
Place the prepared
sample into the cell
holder. Tightly cover the
sample cell with the
instrument cap.