Zirconia material is a kind of zirconia solid electrolyte, which is stable zirconia ceram sinter formed by high temperature sintering of pure zirconia with certain calcia or yttrium oxide. There are oxygen ion holes in its cubic lattice, so in high temperature condition it is a good oxygen ion conductor.
By this specific property, in certain temperature, when there are different oxygen contents at both sides of sensor, it is a typical oxygen concentration cell. If pure platinum electrode is coated on inside and outside of zirconia tube, the zirconia tube is heated by electric stove, and its inner and outer wall contact gas with different oxygen contents, the zirconia tube is an oxygen concentration cell. The following reaction will occur on both platinum electrodes.
For electrode at air side (reference gas side): O2+4e→2O2-
For electrode at low oxygen side (measured side): 2O2 – →O2+4e
After the two kinds of migration reach balance, an electric potential signal E related to oxygen concentration occurs between electrodes.
| Measured object||Concentration of gas or mixed gas of various industrial furnaces and ovens|
|Measure element:||Circonia tube|
|Oxygen measure range:||0~20.6% O2 or 0~10% O2|
|Precision of the instrument:||Intrinsic error of system measure within ±2% full range|
|Precision of transmitter:||1.0 class (within 1.0% full range)|
|Precision of temperature control||Ionstant temperature point 700±2ºC|
|Response time:|| ≤ 3 sec, (reaching 90%|
|Alarming output:||Upper and lower limit outputs, “normally open” or “normally close” point optional|
|Analogue output signal:||4~20mA ADC (load 0Ω~750Ω) corresponding to oxygen content 0~10% O2 or 0~20.6% O2|
|Background correction range:||-20 mV ~ + 20 mV|
|Digit display mode:||LED four nixie light|
|Power consumption:||< 6W (non-including heating power)|
|Heating power:||About 50W (average), able to supply 150W power output|
|Weight:||Detector about 10 kg, converter about 5 kg|