Answer / rambalaji

1. zirconia oxygen analyzers determine oxygen concentration using the conductivity of a zirconia ceramic cell. Zirconia ceramic cells only allow oxygen ions to pass through at high temperatures (750oC). With reference gas on one side and sample gas on the other, oxygen ions move from the side with the highest concentration of oxygen to that with the lowest concentration. The movement of ions generates an EMF (Electro Motive Force) which can be measured to determine the oxygen content

2. The sensor does not actually measure oxygen concentration, but rather the difference between the amount of oxygen in the flue gas and the amount of oxygen in the air. Rich mixture causes an oxygen demand. this demand Causes high voltage to build up due to transportation of oxygen ions through the sensor layer. Lean mixture causes low voltage since there is oxygen Excess. Sensor working in Nernst Principle
In flue gas side O2 is low : High Voltage

In flue gas side O2 is high : Low Voltage

High Concentration : O2 + 4 e  2O2 -

Low Concentration : 2O2 -  O2 + 4 e

0% O2 = 0.82 mv

5% O2 = 0.40 mv

21% O2 = 0 mv

Answer / manikandana

. When temperature increases the content of oxygen decreases.- principle.
Reference gas(span gas) instrument air 21% O2.
1% gas should provide from cylinder for cal purpose.

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