Emerson Rosemount 1056, Instruction Manual

Page: 89 / 126

The following sub-sections show the initial display
screen that appears for each calibration routine. Use
the flow diagram for Conductivity calibration at the
end of Sec. 7 and the live screen prompts for each rou-
tine to complete calibration.
The adjacent screen appears after selecting
Conductivity calibration:
To calibrate contacting conductivity:
1. Press the MENU button
2. Select Calibrate. Press ENTER.
3. Select Sensor 1 or Sensor 2 corresponding to
contacting conductivity. Press ENTER.
4. Select Conductivity. Press ENTER.
The adjacent screen will appear. To calibrate
Conductivity or Temperature, scroll to the desired item
and press ENTER.
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N Calibrate?
Conductivity
Temperature
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N Calibration
Zero Cal
In Process Cal
Meter Cal
Cell K: 1.00000/cm
7.4 Contacting Conductivity Calibration
7.4.1 Description
PLACING A NEW CONDUCTIVITY SENSOR IN SERVICE
New conductivity sensors rarely need calibration. The cell
constant printed on the label is sufficiently accurate for most
applications.
CALIBRATING AN IN-SERVICE CONDUCTIVITY SENSOR
1. After a conductivity sensor has been in service for a period
of time, recalibration may be necessary. There are three
ways to calibrate a sensor.
a. Use a standard instrument and sensor to measure the
conductivity of the process stream. It is not necessary to
remove the sensor from the process piping. The temperature
correction used by the standard instrument may not exactly
match the temperature correction used by the Model 1056.
To avoid errors, turn off temperature correction in both the
analyzer and the standard instrument.
b. Place the sensor in a solution of known conductivity and
make the analyzer reading match the conductivity of the
standard solution. Use this method if the sensor can be easily
removed from the process piping and a standard is
available. Be careful using standard solutions having
conductivity less than 100 µS/cm. Low conductivity standards
are highly susceptible to atmospheric contamination. Avoid
calibrating sensors with 0.01/cm cell constants against
conductivity standards having conductivity greater than 100
µS/cm. The resistance of these solutions may be too low for
an accurate measurement. Calibrate sensors with 0.01/cm
cell constant using method c.
c. To calibrate a 0.01/cm sensor, check it against a standard
instrument and 0.01/cm sensor while both sensors are
measuring water having a conductivity between 5 and 10
µS/cm. To avoid drift caused by absorption of atmospheric
carbon dioxide, saturate the sample with air before making
the measurements.
To ensure adequate flow past the sensor during calibration,
take the sample downstream from the sensor. For best
results, use a flow-through standard cell. If the process
temperature is much different from ambient, keep
connecting lines short and insulate the flow cell.
THIS SECTION DESCRIBES HOW TO CALIBRATE THE MODEL 1056 WITH AN ATTACHED CONTACTING
CONDUCTIVITy SENSOR. THE FOLLOWING CALIBRATION ROUTINES ARE COVERED.
A detailed flow diagram is provided at the end of Sec. 7 to guide you through the calibration routines
Measure Sec. Menu function: default
Description
Contacting
Conductivity
7.4.2 Cell K: 1.00000/cm Enter the cell Constant for the sensor
7.4.3 Zero Cal Zero the analyzer with the sensor attached
7.4.4 In Process Cal Standardize the sensor to a known conductivity
7.4.5 Meter Cal Calibrate the analyzer to a lab conductivity instrument
7.4.6
Cal Factor: 0.95000/cm Enter the Cal Factor for 4-Electrode sensors from the sensor tag
TABLE 7-3 Contacting Conductivity Calibration Routines
Instruction Manual
LIQ-MAN-1056
Section 7.0: Calibration
April 2017