Thermo orion 410Aplus, Instruction Manual

Page: 23 / 129

Benchtop pH/ISE Meter Instruction Manual
Calibration and Measurement of pH 22
pH Calibration Procedure
1. Connect electrode(s) to meter. Choose buffer(s), which is closest to or
will bracket the expected sample pH.
2. Press calibrate. Calibrate is displayed. The time and date of the last
calibration are displayed.
3. After a few seconds ENTER NO. BUFFERS is displayed. Enter the
number of buffers; 1, 2, or 3, and press yes.
4. Rinse electrode(s) and place into first buffer When the electrode signal
is stable, the meter will display the temperature corrected value for
the buffer.
5. When READY CAL AS is displayed, press yes if the value is correct
for your buffer. If performing a manual calibration, use the numeric
keys to change the value, then press yes.
6. If 2 or 3 buffers were selected, repeat steps 4 and 5 for each buffer.
7a. If one buffer was selected, the actual slope value in memory is
displayed at the SLOPE prompt. Press yes if correct, or enter correct
value and then press yes. If actual slope is unknown, enter 100.0 or
perform a two point calibration.
7b. If two or three buffers were selected, the actual electrode slope is
displayed at the SLOPE prompt. If more than two buffers were used,
the slope displayed is an average of the different segments.
8. The meter automatically proceeds to measure mode.
9. Rinse electrode(s) and place into sample. Record pH value from the
main field when READY is indicated or when the electrode signal is
stable. Temperature is displayed on the prompt line.