Measuring Samples Using Standard Additions - Hach sension 4 Instruction Manual

SECTION 3,
continued

3.7 Measuring Samples Using Standard Additions

3. Record or store the concentration or mV value. See
SECTION 4 on page 41 to store or recall data.
4. Remove the electrode from the sample, rinse with deionized
water, and blot dry. Place the electrode in the next prepared
sample. Repeat steps 1–3 for each sample.
5. When measurements are complete, press the
turn the meter off. Rinse the electrode with deionized water
and blot dry. Replace the protective cap on the electrode. For
proper electrode storage, see the electrode manual for
specific instructions.
This method should only be used within the linear range of the
sensing electrode (see the electrode manual). In this mode, the
user may also set the stabilization criteria for the channel used.
The slope of the electrode being used must be known.
1. If necessary, add ISA to the sample. Rinse the electrode and
blot dry. Place the electrode in the sample.
2. Select the desired channel. From the Reading mode, press
.
STD ADDN
3. The display will show
units will be flashing. Use the arrow keys to scroll to the
desired units, then press
4. The display will show the slope that was used for the last
standard addition measurement. If desired, enter another
value using the numerical keypad. To enter a negative slope,
enter the number first, then press the
– sign should appear in front of the slope. Press
5. The display will show
for the sample volume.
6. To change the sample volume, use the numerical keypad.
When entry is complete or no change is needed, press
7. The meter will measure the sample for a baseline voltage.
will appear until the mV reading is stable.
Stabilizing...
39
STANDARD ADDITIONS
.
ENTER
REVIEW/
, , a flashing
Sample mL
key to
I/O/EXIT
, and the
. ± key. The
.
ENTER
, and a value
?
.
ENTER