Incremental
Techniques
|
Section 6
9. Rinse the electrode (ATC probe, stirrer probe and reference electrode, if applicable) with
distilled water, blot dry with a lint-free tissue and place the electrode(s) into the sample.
When the electrode and sample are ready, press the f2 (next) key.
10. Wait for the reading to stabilize. When the reading is stable, press the f2 (yes) key.
11. Use the numeric keypad and decimal key to enter the volume of the standard, in mL, to be
added to the sample and press the f2 (accept) key.
12. Add the standard to the sample and press the f2 (yes) key.
13. Wait for the reading to stabilize. When the reading is stable, press the f2 (yes) key.
14. The meter will display the result of the single known addition. Press the f3 (log/print) key to
save and end the single known addition, export the data to the data log and export the data
to a printer or computer, if a printer or computer is connected to the meter and enabled in
the setup menu.
Note: Press the f1 (escape) key to return to the measurement mode without saving the single
known addition.
15. Press the f2 (next) key.
16. To perform a single known addition using the values that were entered for the previous
single known addition, press the f2 (yes) key. To perform a single known addition and enter
new values, press the f3 (no) key. To end the incremental technique and return to the
measurement mode, press the f1 (escape) key.
Thermo Scientific
Orion Dual Star pH/ISE Benchtop Meter User Manual
|
53
Section 6
|
Incremental Techniques
Double Known Addition
•
For most double known addition analysis, it is recommended that:
o The sample volume should be 100 mL.
o The concentration of the standard added should be 100 times the expected sample
concentration.
o The volume of the first addition should be 1 mL and the volume of the second addition
should be 10 mL.
•
Refer to the appropriate electrode user guide for instructions for preparing the electrode,
required solutions (ionic strength adjusters, standards, etc) and any special requirements.
•
Ensure that the electrode, ATC probe and reference electrode (if applicable) are connected
to the meter inputs that correspond with the selected channel.
Double Known Addition Procedure
1. Prepare the sample as directed in the electrode user guide.
2. In the measurement mode, press the setup key. Press the ▲ / ▼ keys to highlight
Incremental Techniques and press the f2 (select) key.
3. Dual channel display only: Press the ▲ / ▼ keys to select the channel to perform the
double known addition on and press the f2 (accept) key.
4. Press the ▲ / ▼ keys to highlight Double Known Addition and press the f2 (select) key.
5. Use the numeric keypad and decimal key to enter the sample volume, in mL, and press the
f2 (accept) key.
6. Use the numeric keypad and decimal key to enter the total volume, in mL, and press the
f2 (accept) key. The total volume includes the sample volume, ISA volume and diluting
agent volume, but not the standard volume.
7. Use the numeric keypad and decimal key to enter the concentration of the standard and
press the f2 (accept) key.
8. Rinse the electrode (ATC probe, stirrer probe and reference electrode, if applicable) with
distilled water, blot dry with a lint-free tissue and place the electrode(s) into the sample.
When the electrode and sample are ready, press the f2 (next) key.
9. Wait for the reading to stabilize. When the reading is stable, press the f2 (yes) key.
10. Use the numeric keypad and decimal key to enter the volume of the first increment of
standard, in mL, to be added to the sample and press the f2 (accept) key.
11. Add the first increment of standard to the sample and press the f2 (yes) key.
12. Wait for the reading to stabilize. When the reading is stable, press the f2 (yes) key.
54
|
Orion Dual Star pH/ISE Benchtop Meter User Manual
Thermo Scientific
Incremental
Techniques
|
Section 6
13. Use the numeric keypad and decimal key to enter the volume of the second increment of
standard, in mL, to be added to the sample and press the f2 (accept) key.
14. Add the second increment of standard to the sample and press the f2 (yes) key.
15. Wait for the reading to stabilize. When the reading is stable, press the f2 (yes) key.
16. The meter will display the result of the double known addition. Press the f3 (log/print) key to
save and end the double known addition, export the data to the data log and export the data
to a printer or computer, if a printer or computer is connected to the meter and enabled in
the setup menu.
Note: Press the f1 (escape) key to return to the measurement mode without saving the double
known addition.
17. Press the f2 (next) key.
18. To perform a double known addition using the values that were entered for the previous
double known addition, press the f2 (yes) key. To perform a double known addition and
enter new values, press the f3 (no) key. To end the incremental technique and return to the
measurement mode, press the f1 (escape) key.
Thermo Scientific
Orion Dual Star pH/ISE Benchtop Meter User Manual
|
55