Section 7: Calibration
7.1
Calibration - Introduction
Calibration is the process of adjusting or standardizing the analyzer to a lab test or a calibrated
laboratory instrument, or standardizing to some known reference (such as a commercial buffer).
The auto-recognition feature of the analyzer will enable the appropriate calibration screens to allow
calibration for any single sensor configuration or dual sensor configuration of the analyzer.
Completion of Quick Start upon first power up enables live measurements but does not ensure
accurate readings in the lab or in process. Calibration should be performed with each attached
sensor to ensure accurate, repeatable readings. This section covers the following programming and
configuration functions:
1. Auto buffer cal for pH (pH Cal -
Section 7.2
)
2. Manual buffer cal for pH (pH Cal -
Section 7.2
)
3. Set calibration stabilization criteria for pH (pH Cal -
Section 7.2
)
4. Standardization calibration (1-point) for pH, ORP and Redox (pH Cal -
Section 7.2
and
7.3
)
5. Entering the cell constant of a conductivity sensor (Conductivity Cal -
Section 7.4
and
7.5
)
6. Calibrating the sensor in a conductivity standard (Conductivity Cal -
Section 7.4
and
7.5
)
7. Calibrating the analyzer to a laboratory instrument (Conductivity Cal -
Section 7.4
)
8. Enter a manual reference temperature for temperature compensation of the process measurement
7.2
pH Calibration
7.2.1
Description
New sensors must be calibrated before use. Regular recalibration is also necessary. Use auto
calibration instead of manual calibration. Auto calibration avoids common pitfalls and reduces errors.
The analyzer recognizes the buffers and uses temperature-corrected pH values in the calibration.
Once the Model 1057 successfully completes the calibration, it calculates and displays the calibration
slope and offset. The slope is reported as the slope at 25 °C. This section describes how to calibrate the
model 1057 with a ph sensor. the following calibration routines are covered.
A detailed flow diagram is provided at the end of this section to guide you through the calibration
routines.
To calibrate pH:
1.
Press the
MENU
button
2.
Select
Calibrate
. Press
ENTER
.
3.
Select
Sensor 1
or
Sensor 2
corresponding to pH. Press
ENTER
.
4.
Select
pH
. Press
ENTER
.
Measure Section Menu Function
Default
Settings
Description
pH
7.2.2
Auto Calibration
pH
Two point buffer calibration with auto buffer recognition
7.2.3
Manual Calibration pH
Two point buffer calibration with manual buffer value entry
7.2.4
Entering A Known
Slope Value
pH
Slope calibration with manual entry of known slope value
7.2.5
Standardization
pH
One point buffer calibration with manual buffer value entry
Table 7-1 pH calibration routines
Instruction Manual
LIQ-MAN-1057
Section 7: Calibration
April 2017
Section 7: Calibration
41
