Thermo Orion 410Aplus, Instruction Manual

Page: 49 / 131

Orion Benchtop pH/ISE Meter Instruction Manual
Special Features 45
Double Known Addition Measurement Procedure
For most double known addition analysis, it is recommended that:
a. Sample volume be 100 mL.
b. The concentration of the standard added be 100 times the
expected sample concentration.
c. The volume of the first addition be 1 mL.
d. The volume of the second addition be 10 mL.
The following table is a sequence of key presses and prompts displayed
when performing a double known addition. (Numbers and electrode ID are
used for illustration purposes only.)
Prompt Key Press/Action
1. Press 2nd then incr tech .
2. 1-ADDN 2-SUBTR Press 1 , then yes .
3. KNOWN ADDN The meter verifies your choice.
Wait for the next prompt.
4. 1-SINGLE 2-DOUBLE Press 2 , then yes .
5. DOUBLE The meter verifies your choice
KNOWN ADDN then continues.
6. SAMPLE VOLUME? Enter the volume of the sample.
Press
yes .
7. TOTAL VOLUME? Enter the total volume in the beaker.
For example if you have 100 mL of
sample and 10 mL of diluent, enter
110. Press
yes .
8. STD CONC? Enter the concentration of the
standard to be added to the sample.
Press
yes .
9. 1-NA+ IN SAMPLE? Rinse electrode(s) and place into
sample and press
yes .
10. MEASURING SAMPLE When the electrode signal is stable
1-NA+ READY press yes .
YES TO CONTINUE
11. 1ST STD VOLUME? Enter the volume of standard to be
added to the sample. Press
yes .
12. ST STD ADDED? Add standard to sample, then
press
yes .