Hach DR/850, Procedures Manual, Page: 422 / 460

422
Sampling and Storage
Collect samples in clean plastic or glass bottles. Analyze samples
as soon as possible after collection. The sample may be stored
seven days by cooling to 4 °C (39 °F).
Method Performance
Precision
In a single laboratory, using a standard solution of 847.4 mg/L
Suspended Solids with the instrument, a single operator obtained
a standard deviation of
±
18.2 mg/L Suspended Solids.
For more information on Hach’s precision statement,
see
Section 1 .
Estimated Detection Limit
The estimated detection limit for program 94 is 22.1 mg/L
Suspended Solids. For more information on the estimated
detection limit, see
Section 1 .
Interferences
Calibration for this test is based on parallel samples using the
gravimetric technique on sewage samples from a municipal
sewage plant. For most samples, this calibration will provide
satisfactory results. When higher accuracy is required, run
parallel photometric and gravimetric determinations with
portions of the same sample. The new calibration should be
made on your particular sample using a gravimetric technique as
a basis.
9.
Swirl the prepared
sample cell to remove
any gas bubbles and
uniformly suspend
any residue.
10.
Place the prepared
sample into the cell
holder. Tightly cover the
sample cell with the
instrument cap.
11.
Press:
READ
The cursor will move to
the right, then the result
in mg/L suspended
solids will be displayed.
SUSPENDED SOLIDS,
continued