Emerson Rosemount 56 - Ozone Calibration

Section 10: Calibration Instruction Manual
April 2017 LIQ-MAN-56
84 Calibration
1. To Zero Calibrate the analyzer with
the sensor attached, follow the step-
b
y-step procedures displayed on-
screen.
2. To Air Cal Calibrating the sensor in a
water-saturated air sample, follow
the step-by-step procedures dis-
played on-screen.
3. To perform an In-Process Calibration
by Standardizing the sensor, follow
the step-by-step procedures displayed on-screen.
4. To calibrate the oxygen sensor by manually Entering a known slope value for sensor re-
sponse, follow the step-by-step procedures displayed on-screen.
10.8 Calibration — Ozone
An ozone sensor generates a current directly proportional to the concentration of ozone in
the sample. Calibrating the sensor requires exposing it to a solution containing no ozone
(zero standard) and to a solution containing a known amount of ozone (full-scale standard).
The Zero Calibration is necessary because ozone sensors, even when no ozone is in the
sample, generate a small current called the residual or zero current. The analyzer
compensates for the residual current by subtracting it from the measured current before
converting the result to an ozone value. New sensors require zeroing before being placed in
service, and sensors should be zeroed whenever the electrolyte solution is replaced. The best
zero standard is deionized water. The purpose of the In Process Calibration is to establish the
slope of the calibration curve. Because stable ozone standards do not exist, the sensor must
be calibrated against a test run on a grab sample of the process liquid. Several manufacturers
offer portable test kits for this purpose.
To calibrate the ozone sensor, access the Calibration screen by pressing ENTER/MENU from the
main screen, select S1 or S2 Measurement and press ENTER/MENU. Press INFO at any time to
learn more about this procedure. A yellow
screen will appear with detailed
instructions and information.
The following calibration routines are
covered:
1. Zero Cal Zeroing the sensor in
solution with zero total chlorine
2. Grab Cal Standardizing to a sample of
known ozone concentration
1. To Zero Calibrate the analyzer with
the sensor attached, follow the step-
by-step procedures
displayed on-screen.
2. To perform a Grab Calibration by
Standardizing the sensor, follow the
step-by-step procedures displayed
on-screen.