Hach DR/850, Procedures Manual, Page: 437 / 460

437
Method 8237
TURBIDITY
(0 to 1000 FAU)
For water, wastewater, and seawater
Absorptometric Method
*
* Adapted from FWPCA Methods for Chemical Analysis of Water and Wastes , 275 (1969)
1.
Enter the stored
program number for
turbidity.
Press:
PRGM
The display will show:
PRGM ?
Note:
1 FAU=1 NTU=1 FTU
when measuring formazin.
These are not equivalent
when measuring other
types of standards or
samples.
2.
Press:
95 ENTER
The display will show
FAU and the ZERO
icon.
3.
Fill a sample cell
with 10 mL of deionized
water (the blank).
Note: Wipe the surface of
the cell with a soft cloth.
Note: For highly colored
samples, use a filtered
portion of sample in place
of the deionized water.
4.
Place the blank into
the cell holder. Tightly
cover the sample cell with
the instrument cap.
5.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0 FAU
6.
Fill another sample
cell with 10 mL of
sample.
Note: Mix the sample well
before transferring it to the
sample cell.
Note: Wipe the surface of
the cell with a soft cloth.
7.
Place the sample cell
into the cell holder.
Tightly cover the sample
cell with the
instrument cap.
8.
Press:
READ
The cursor will move to
the right, then the result
in Formazin Attenuation
Units (FAU) will be
displayed.
Note: Standard Adjust may
be performed using a
prepared standard (see
Section I).