4.2
Span Calibration using a Certified Span Gas
Calibration involves using a known span gas to match and adjust the oxygen sensor / ana-
lyzer combo to a known value. This can be as simple as using ambient air that tends to be a
constant 20.9% or a bottle of certified span gas from your local air separation company. For
this section, we will focus on using a certified span gas from your local air separation compa
-
ny. When using a certified bottle, it is recommended to get a span gas equal to 90% or higher
of the range you want to use. If you are measuring in the 0 - 1000ppm range, a 900 ppm
nitrogen with a balance of oxygen would be ideal.
For a recommendation on which type of calibration is best for your process consult the fac-
tory.
Calibration using Certified Span Gas:
It is recommended to read through the calibration prior to performing an air calibration to
ensure all instructions are understood. Consult the factory if any questions arise.
Note: For a new trace oxygen sensor (TO2-1x or TO2-2x), purging with a
zero gas for 4 - 6 hours will help the low end stability and response. This
is not necessary on a percent or purity sensor.
Connect the gas sample line and set the pressure / flow per section 2.4
of the users manual.
Once the gas is flowing, let the reading stabilize for about 5 - 10 minutes
and then proceed (consider longer if sensor is still trending down, very
important when trying to calibrate with a low span gas such as 5 ppm o2 /
balance nitrogen).
SPAN CALIBRATION: To calibrate the indicator, press the MENU key
and use the UP/DOWN keys to highlight the SPAN
CAL option 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 8.09 ppm
adjust the display UP or DOWN until it reads 8.09 ppm.
Press the ENTER key and 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 not be exposed to ambi-
ent air for more than 2 minutes. This will help speed of response, sensor
life, and low end sensitivity.
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
Maintenance
OMD-525X Oxygen Analyzer
8.09
PARTS PER MILLION
UP TO INCREASE
DOWN TO DECREASE
ENTER TO CAL
ESC TO EXIT
MAIN MENU
AUTO RANGE
MANUAL RANGE
SPAN CAL
ZERO CAL
SET TIME
SET DATE
CONFIG ALARM 1
CONFIG ALARM 2
LOGGING INTERVAL
SYSTEM
