Part 4 Maintenance
4.1
Span Calibration using Ambient Air
Calibration involves using a known span gas to match and adjust the oxygen sensor / analyzer
combo to a known value. This can be as simple as using ambient air that tends to be a constant
20.9% which is what we will focus on for section 4.1. For calibrating with a certified SPAN gas,
please proceed to section 4.2. For a decision on which type of calibration is good for your ap-
plication, consult the factory for a recommendation.
Calibration using Ambient Air:
If using ambient air to calibrate the sensor, it is recommended to read
through the calibration proceedure prior to performing an air calibration
to make sure all instructions are understood. Consult the factory if any
questions arise.
If the sensor is already installed in the sensor housing, you will need to
open up the H3 flow housing and with two fingers, hold the sensor to
the top portion of the housing, making sure the sensor PCB contacts are
firmly touching the gold pogo pins on the housing.
Let the reading stabilize for about 1 minute and than proceed to the following
steps in the OMD-480 menu:
SPAN Calibration: To calibrate the analyzer, press the MENU key, use the
UP / DOWN keys to bring the cursor besides the option SPAN CAL and
press ENTER.
Use the UP / DOWN keys to set the required value. You can shift to the next
digit by pressing the ENTER key. A final enter is needed to save the value and
change the display.
Once ENTER has been pressed, the display will show PASSED or FAILED. If
Passed, promptly put the sensor back into the sensor housing and you can
begin to monitor your process application. If FAILED, repeat steps and contact
the factory if questions arise.
CALIBRATE WITH SPAN GAS:
To calibrate with a span gas, you will follow the same proceedure within the menu however
instead of exposing the sensor to ambient air, you will install the sensor making sure the screen
side is facing down and the gold PCB’s are facing up to make contact with the gold pogo pins.
You can than hook your calibration gas up to the Inlet port (Note: it does not matter which port
is the inlet and which port is the outlet on the sensor housing). Set the gas flow rate between
0.5 - 5.0 SCFH and let the ready stabilize. Proceed to calibration proceedure within the menu.
