Analytical Industries AII-2000 M Oxygen Analyzer - Manual (Page 13)

Calibrate at the temperature and pressure (altitude) at which the ana-
lyzer will be operated, humidified gases cannot be 100% oxygen.
Effect of Condensation
Excessive condensation collecting on the sensing area or the electrical connec-
tions at the rear of the sensors can adversely impact the performance of elec-
trochemical sensors. Condensation blocks the diffusion path of oxygen into the
sensor and can reduce the oxygen reading to 00.0 if the condensation covers
the entire sensing area. Condensation on the electrical connections at the rear
of the sensor can affect oxygen readings. Remedy either situation by shaking
out the condensation and allowing the sensor to air dry.
Erroneously characterized in many instances as a sensor failure, excessive
condensation is remedied by gently wiping away the condensation with a soft
cloth or simply allowing the sensor to air dry.
Effect of Electromagnetic Radiation
Tested over a 26 MHz to 1000 MHz electromagnetic field, the analyzer is sus-
ceptible at all frequencies tested except those between 930 and 990 MHz.
Never operate the analyzer near equipment capable of emitting high
levels of electromagnetic radiation. Do not continue to operate the
analyzer if the reading becomes unstable.
Calibration
Calibrating the analyzer or monitor during normal operation involves
the same precautions and procedures as those described in Sections
4.7 Start-up Calibration with the same cautions to review Sections 3
Safety Warnings and 5.2 Application Considerations.
5.4 Sampling
Assuming the START-UP instructions are followed and the tests are completed
successfully the devices default to the SAMPLING mode.
Never operate the analyzer if the reading is unstable or if a malfunction
is suspected. If calibration is required as indicated herein, do not pro-
ceed until the analyzer is calibration successfully.
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5.4.1 Flowing Gas Streams (Breathing Circuits)
1. Place the sensing area of the sensor into the gas stream to be analyzed
upstream of any humidification equipment.
2. Assure that the flow rate of the gas stream does not exceed ten (10) liters
per minute. Exceeding ten (10) liters per minute generates backpressure.
3. Check the gas stream and particularly the mechanical connection for leaks
that dilute the gas stream with ambient air.
4. Assure there are no restrictions in the circuit downstream of the sensor
that could generate backpressure on the sensor.
5. Use the flow diverter supplied with the device along
with the optional tee adapter and position the sen-
sor vertically for optimum results, as shown right.
The flow diverter avoids stagnation and facilitates
the movement of gas to and from the sensing area
of the sensor thereby producing a more accurate
measurement of the gas stream to be measured.
6. Install the tee-adapter in the breathing circuit.
7. Screw the flow diverter to the sensor.
8. Ensure the o-ring is lightly lubricated for ease of
entry and a tight seal between the flow diverter and
tee adapter.
9. Insert the assembled flow diverter/sensor into the tee allowing 100%
oxygen (dry, non-humidified) to flow past the sensor at a rate of 5-8 liters
per minute.
10. Once the sensing area of the sensor is exposed to the gas stream allow
approximately sixty (60) seconds for the reading to stabilize and observe
the reading displayed by the LCD.
5.4.2 Static Atmospheres (Incubators, Hoods, Oxygen Tents)
Remove the flow diverter, not needed. Failure to remove the flow diverter will
dramatically slow the response time of the sensor.
Expose the sensing area of the sensor to the atmosphere allowing approxi-
mately sixty (60) seconds for the reading to stabilize and observe the reading
displayed by the LCD.
If placing the entire sensor inside the controlled atmosphere review
Section 5.2 Application Consideration, Effect of Temperature.
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