Oxygen Analyzers Flashcards
What are the two categories of oxygen analyzers? Which analyzers require cool gas
samples? Which analyzers can be used with hot gases?
1) Paramagnetic: includes Magneto-dynamic, and thermo-magnetic
2) Electrochemical: includes Zirconium Oxide cell analyzers, polarographic, and galvanic
Zirconium Oxide cells can be used in-situ with hot gasses
Besides oxygen, what other gases are paramagnetic?
Nitrogen, Nitrogen Dioxide, and Chlorine Dioxide
When oxygen is introduced into a deflection type (magneto-dynamic) oxygen analyzer, it
____________________ the magnetic field strength, ______________________ the
deflection of the glass balls
intensifies, increasing
How is the position of the dumbbell tracked in the deflection type oxygen analyzer?
Light reflection off a mirror that is attached to the dumbbells
What signal is measured to determine the concentration of oxygen in a deflection type
oxygen analyzer?
Feedback current required to return the dumbbells to the start position. The more Oxygen that passes through the cell, the more current is required.
What is the minimum operating temperature of a zirconium oxide cell?
600 C
What would be the effect on the displayed oxygen concentration if a ZrO2 sensor’s
temperature detector went out of calibration and transmitted a falsely low reading?
The displayed Oxygen concentration would decrease as the difference between reference gas and sample gas would be smaller.
What are the advantages of using an in situ placement of a zirconium oxide probe?
1) Does not require a sample handling system as it is in-situ
2) No transport lag time
3) No contamination by air
4) Less maintenance required as there is no SHS to maintain
What is net oxygen and when are net readings taken? How do they compare to the true
(gross) oxygen concentration in the sample gas?
Net Oxygen readings are taken by a Zirconium Oxide cell and refer to the difference between reference and sample gasses.
Gross Oxygen readings are taken by the Magneto/Thermo-magnetic Oxygen cells and refer to the combined Oxygen concentration. Gross readings will be larger.
Would a wet O2 reading be higher or lower than a dry O2 reading? Which sensor(s) take(s)
wet readings?
Wet reading taken by a Zirconium Oxide cell will always be lower.
Which Oxygen analyzers need a dry sample?
Magneto, and Thermomagnetic
Which Oxygen analyzer can take a wet sample?
Zirconium Oxide as the probe is in-situ and does not require a SHS.
Thermo-magnetic cells measure the difference in _______________.
Resistance
What are the disadvantages of thermo-magnetic/magneto Oxygen cells?
1) Need a dry sample therefore require a SHS
2) Experience interference from other paramagnetic gasses
3) Require temperature control
