GE Baker Hughes oxy.IQ, User Manual

Page: 29 / 91

Chapter 3. Initial Setup & Operation
oxy.IQ User’s Manual 19
3.3.4 Span Gas Calibration
Before beginning the span gas calibration, make sure the oxy.IQ is
indicating an O
2
level less than the span gas value, to ensure an
accurate calibration. Then, start the flow of the span gas to the
sensor. For accurate calibration, the span gas should have an oxygen
content of 70-90% of the range being calibrated.
To perform the span calibration, complete the following steps:
1.
Use the equation below to calculate the expected mA output that
corresponds to the known oxygen content of the span gas:
For example, if the span gas contains 80 ppm oxygen and the
0-100 ppm range is being calibrated, the analog output should equal
4 + 16 x (80/100) = 16.8 mA.
2.
If you have not done so already, start the flow of span gas to the
sensor and allow both the 4-20 mA output reading and the
display reading to stabilize.
3.
After the reading has stabilized, press the
Enter
key to enter
the Main Menu .
4.
Press the
Enter
key to enter the Calibration menu.
5.
Press the key and then press the
Enter
key to select the
Span Gas menu option.
6.
Press the and keys until the measurement agrees with the
span calibration gas value.
7.
Confirm that the reading on the display has stabilized, and press
the
Enter
key to save the calibration. Then, press the
Cancel
key twice to return to measurement mode.
4.0 16.0
Span Gas ppm
Full Range ppm
--------------------------------------

+ mA Output =