PART THREE - OPERATION
SECTION 4 - ANALYZER CALIBRATION
Rev. 6-1100
Model P33 pH/ORP Analyzer (panel-mount 1/4 DIN)
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9.
Determine the pH value of the sample using laboratory
analysis or a calibrated portable pH meter. (When using
a pH buffer, refer to the table on the buffer bottle to find
the exact pH value corresponding to the temperature of
the buffer.)
10. With the static
screen displayed,
use
arrow keys
to adjust the displayed value to exactly
match the known pH value of the sample (or buffer).
Then press
ENTER key
to enter the value, completing
calibration of the point.
11. A “pH SLOPE XX.X mV/pH” screen appears, indicating
a slope value to measure sensor performance. The
slope should be between 54 and 62 mV/pH for optimal
sensor performance. Typically, as the sensor ages
and/or becomes dirty, its slope decreases. When the
slope decreases below 54 mV/pH, clean the sensor to
improve its performance. If the slope remains low and
you are using a GLI Differential sensor, replace the salt
bridge and standard cell buffer (see sensor instruction
manual for details). If using a conventional combination
electrode, consider replacing it.
12. Press
ENTER key
to end calibration (“1 POINT
SAMPLE: CONFIRM CAL OK?” screen appears).
13. Re-install the sensor into the process.
14. Press
ENTER key
to display the active measurement
reading on the “1 POINT SAMPLE: CONFIRM ACTIVE?”
output status screen. When the reading corresponds to
the actual typical process value, press
ENTER key
again to return the analog outputs and relays to their
active states (MEASURE screen appears).
This completes “1 POINT SAMPLE” calibration.
