In-Situ RDO PRO Process Optical Dissolved Oxygen Sensor Manual - Manual (Page 22)

12. Write the Calibration Mode Off command (0xE002) to the sensor command register to place the
sensor in normal operation. If the calibration mode is turned off without a calibration update
command, or the calibration command returned an exception, the previous calibration shall be
restored.
13. Optional: If you saved the temperature and saturation parameter units at the start of the
process, write the original values back.
14. Optional: If you saved the Sensor Data Cache Timeout register 9463 at the start of the process,
write the original value back.
6.5.1 Calibration Calculations
Calibrated oxygen reading:
O
2RC
= c
o
+ c
1
× O
2RU
Where:
c1 = (O
2
100%Sat)/( O
2RUS
− O
2RUZ
)
c
o
= -c
1
× O
2RUZ
Where:
O
2
100%Sat is the theoretical 100% saturation point
O
2RUS
is the un-calibrated reading at 100% saturation
O
2RUZ
is the un-calibrated reading at 0% saturation
References:
Standard Methods for the Examination of Water and Wastewater, 20 th Ed, 2008. 4500-0 C. Azide
Modification. American Public Health Association. USA.
Page 22 Modbus Registers