Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 166)

<14. CALIBRATION OF DO (Dissolved Oxygen)>
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IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
14. CALIBRATION OF DO (Dissolved Oxygen)
Calibrate dissolved oxygen sensors after installing or replacing them, cleaning the membrane, or
replacing the electrolyte solution.
Air, water, and manual calibrations are available.
Air calibration is the most common and easiest method. Water calibration is more accurate.
Manual calibration uses manually analyzed sample water and adjusts the sensor to the value.
NOTE
A default is “10 min” for “Auto Return”. When maintenance like a calibration that may take much
time is performed, “60 min” or “Disable” is recommended to be selected. (Refer to the section
13.7.3.)
Execute:
Calibration
HOLD
Temporary output
Setup:
Commissioning
Change language
Start Quick Setup
Execute & Setup Calibration
Air calibration
Water Calibration
Manual Slope Cal.
Manual Offset Cal.
Temperature Cal.
Start manual wash cycle
* This appears only when Zero
Calibration is set “Enabled” .
** This appears only when
“PH201G” is selected on the
Communication screen and
Wash contact is enabled. **
*
Figure 14.1 Calibration
The calibration items include “Air calibration,” “Water Calibration,” “Manual Slope Cal,” and
“Temperature Cal.”
When Zero Calibration is set “Enabled” (see section 13.2.6), “Manual Offset Cal.” is available.
Press to select “Execute: Calibration,” choose the calibration object, and configure the
calibration to perform it. Calibration is made stepwise; follow the prompts displayed on the screen
to carry it out.
A stability check is conducted at each measurement point. Proceed to the next step only after the
reading has stabilized.
NOTE
While “CHECKING STABILITY…” is indicated, the instrument automatically checks the stability
of the measurement (input value). If the stability is not confirmed within 60 min, an error is issued
and the procedure is aborted. Change the parameters in the stabilization time and step range as
necessary (see Section 13.2.6), and then recalibrate the sensor.
NOTE
When a sensor or a membrane is exchanged or replaced, sensor wellness data should be reset.
When a sensor is replaced, the replacement can be recorded manually into a logbook. (Refer to
the figure 12.9.)
DO
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