Analytical Industries GPR-35 Oxygen Analyzer - Manual (Page 21)

Advanced Instruments Inc.
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5. Ensure the span gas flows freely: check for obvious leaks and make sure the vent hole in the Calibration Flow Adapter (P/N
A-2344) is not blocked and the gas exits easily.
6. If equipped with SS bulkhead tube fittings
on the side of the analyzer remove the nut
and ferrules of the tube fitting and push the
plastic tubing over the male threads.
7. Insert the flow through adapter into the
opening of the sensor as illustrated below.
Skip this step if the analyzer is equipped
with SS bulkhead tube fittings.
8. Gently seat the flow through adapter and
ensure a good o-ring seal. Skip this step if
the analyzer is equipped with SS bulkhead
tube fittings.
9. Allow the span gas to flow until the reading
stabilizes before adjusting the SPAN
potentiometer.
10. The analyzer should stabilize in 10-15
minutes.
11. If after 30 minutes the oxygen value
displayed is not stable perform a complete
check of all external sample system
connections before concluding the sensor is
defective and notifying the factory.
12. After the reading stabilizes, turn the SPAN
potentiometer ½ turn at a time until the
LED display reads the desired span gas
value of 20.9%
13. Caution: Turning the potentiometer more
the ½ turn recommended does not allow
the electronics sufficient time to keep pace
with the adjustment. And since adjustments
are rarely made in one consecutive turn –
there is a real possibility that the 2
nd and 3 rd
part of the adjustment could unknowingly
be based on “values that have not
stabilized” thereby resulting in an inaccurate
calibration.
14. After calibration is complete, remove the
Calibration Flow Adapter and store it.
15. Proceed to SAMPLING.
Procedure Air Calibration for Above Sensors:
Not recommended unless user confirms the ambient air or atmosphere surrounding the analyzer is not contaminated.
1. The reading should be stable, turn the SPAN potentiometer ½ turn at a time until the LED display reads 20.9%
2. Caution: Turning the potentiometer more the ½ turn recommended does not allow the electronics sufficient time to keep
pace with the adjustment. And since adjustments are rarely made in one consecutive turn – there is a real possibility that
the 2
nd and 3 rd part of the adjustment could unknowingly be based on “values that have not stabilized” thereby resulting in
an inaccurate calibration.
3. Ensure the reading is stabilizes at 20.9%.
4. Proceed to SAMPLING.