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 process 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 procedure 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
connect the gas samples line as noted in section 2.4 or expose the sensor
to ambient air which is typically 20.9%. With the flow through
sensor housing, you can open up the housing and with two fingers, hold
the sensor to the top portion of the housing, making sure the sensor
contacts are firmly touching the gold pogo pins on the housing. Also
make sure the sensing surface (stainless steel mesh) is facing the ground).
Let the reading stabilize for about 30 - 45 seconds and then proceed to
the following steps in the OMD-625 menu:
SPAN CALIBRATION: To calibrate the transmitter, press MENU key
Use UP/DOWN keys to bring cursor besides the option SPAN
CAL and press the ENTER key.
Use the UP / DOWN key until the reading on the display matches
the value of your SPAN Gas. For example if your SPAN gas is 20.9%
adjust the display UP or DOWN until it reads 20.9%.
Once ENTER has been pressed, the display will show “PASSED” or
“FAILED”. If passed, promptly put the sensor in a zero or low oxygen
gas. This will help extend the life of the sensor and speed of response.
If failed, repeat calibration steps or consult the factory.
Trace Oxygen Sensor Caution: The sensor should be exposed to ambient
air for less than 2 minutes. This will help speed of response, sensor life
and low end sensitivity.
Maintenance
OMD-625 Oxygen Analyzer
Designed, Tested and Assembled in California, USA
4045 E. Guasti Rd. #203 Ontario, CA 91761 USA : 1-949-398-2879 : [email protected] : www.sso2.com
20.5%
UP - INCREASE
DOWN - DECREASE
ENTER TO CAL
ESC TO EXIT
MAIN MENU
AUTO RANGE
MANUAL RANGE
SPAN CAL
ZERO CAL
ALARM 1
ALARM 2
SYSTEM
