Thermo orion 410Aplus, Instruction Manual

Page: 46 / 129

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.