Calibration - Chlorine; Calibration - Free Chlorine - Emerson Rosemount 1066 Instruction Manual

Section 9: Calibration
April 2017
9.6 Calibration – Chlorine
The 1066 can measure three variants of Chlorine:
• Free Chlorine
• Total Chlorine
• Monochloramine
The section describes how to calibrate any compatible amperometric chlorine sensor. The
following calibration routines are covered in the family of supported Chlorine sensors:
• Air Cal
• Zero Cal
• In Process Cal
9.6.1
Calibration – Free Chlorine
A free chlorine sensor generates a current directly proportional to the concentration of free
chlorine in the sample. Calibrating the sensor requires exposing it to a solution containing no
chlorine (zero standard) and to a solution containing a known amount of chlorine (full-scale
standard). The zero calibration is necessary because chlorine sensors, even when no chlorine is in
the sample, generate a small current called the residual current. The transmitter compensates for
the residual current by subtracting it from the measured current before converting the result to a
chlorine value. New sensors require zeroing before being placed in service, and sensors should be
zeroed whenever the electrolyte solution is replaced.
To calibrate the chlorine sensor, access the Calibration screen by pressing ENTER from the main
screen and press ENTER.
The following calibration routines are covered:
1. Zero Cal Zeroing the sensor in solution with zero free chlorine
2. Grab Cal Standardizing to a sample of known free chlorine concentration
To calibrate free chlorine:
1. Press the MENU button
2. Select Calibrate. Press ENTER.
3. Select Free Chlorine. Press ENTER.
The adjacent screen will appear. To calibrate Free Chlorine or Temperature,
scroll to the desired item and press ENTER.
The following sub-sections show the initial display screen that appears for each calibration routine.
Use the flow diagram for Chlorine calibration at the end of
to complete calibration.
The adjacent screen appears after selecting Free Chlorine calibration:
76
Instruction Manual
1.234 µS/cm
SN Calibrate?
Free Chlorine
Temperature
Section 7 and the live screen prompts
1.234 µS/cm
SN Calibration
Zero Cal
In Process Cal
LIQ-MAN-1066
25.0 ºC
25.0 ºC
Calibration