Hach DR/850 Procedures Manual page 338

pH,
continued
9.
Press:
READ
The cursor will move to
the right, then the result
in pH units will
be displayed.
Note: Use of the Standard
Adjust feature is highly
recommended. See
Accuracy Check.
Note: Any reading below
6.5 pH units will
be erroneous.
Sampling and Storage
Accuracy Check
Method Performance
Analyze samples immediately for best results.
Standard Solution Method
Using a clear pH 7.0 buffer solution as the sample, perform the
pH procedure as described above.
Precision
In a single laboratory using a standard solution of pH 7.0 and two
lots of reagent with the instrument, a single operator obtained a
standard deviation of less than 0.1 pH units.
Estimated Detection Limit
The estimated detection limit for program 75 is a pH of 6.5.
338