PART THREE - OPERATION
SECTION 4 - ANALYZER CALIBRATION
Model P33 pH/ORP Analyzer (panel-mount 1/4 DIN)
Rev. 6-1100
52
S
ECTION
4
4.1 Important Information
☞
Calibrate Periodically
☞
Temperature-corrected
pH Measurement
Four methods are provided to pH calibration (Section 4.2).
To calibrate ORP, use only the 1-POINT SAMPLE method
described in Section 4.3. The mA value for each analog
output can also be calibrated (Section 4.4).
NOTE:
When the passcode feature is enabled (Section
3.6), you must successfully enter the passcode
before attempting to calibrate the analyzer.
Also, an in-progress calibration can always be
aborted by pressing the ESC key.
After “ABORT:
YES?” screen appears, do one of the following:
•
Press
ENTER key
to abort. After the “CONFIRM
ACTIVE?” screen appears, press
ENTER key
to
return the analog outputs and relays to their
active states (MEASURE screen appears).
•
Press
×
×
or
Ø
Ø
key
to choose “ABORT: NO?”
screen. Press
ENTER key
to continue calibration.
To maintain best measurement accuracy, periodically cali-
brate the analyzer. Performance of the pH (or ORP) sensor
slowly degrades over time, eventually causing inaccurate
readings. The time period between calibrations, and the
rate of system drift, can vary considerably with each appli-
cation and its specific conditions.
Calibration Tip!
Establish a maintenance program to
keep the sensor relatively clean and the analyzer cali-
brated. The periodic intervals for maintenance (days,
weeks, etc.) will be influenced by the characteristics of
the process solution, and can only be determined by op-
erating experience.
The analyzer is factory-calibrated for accurate temperature
measurement. It will provide pH readings that are automati-
cally corrected for temperature changes when the analyzer:
•
Receives a temperature signal from a pH sensor with
a built-in temperature element (all GLI Differential
sensors) or from a separate temperature element.
•
Has been correctly set for the type of temperature
element being used for automatic compensation.
ANALYZER CALIBRATION
