Some questions about zirconia oxygen analyzer

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When the instrument reads a low value, it is because: 1) The sample gas may contain flammable gases. The zirconia solid electrolyte operates at high temperatures of 600–850 degrees Celsius; if flammable gases are present, a combustion reaction occurs that consumes oxygen, resulting in a low reading on the instrument； Handling method: Extract a test sample of the gas; if combustible gases are present, adjust the operating conditions to remove them, or install a purifier to eliminate such gases. 2》The probe filter becomes clogged, resulting in increased air resistance; this is due to a decrease in the diffusion rate of oxygen molecules in the gas being measured ； 3》Excessively high furnace temperature ； 4》The range potential is too high. When the instrument reading is high: 1) The zirconium tube is cracked and leaking air ； 2》Small cracks appeared in the zirconium tube, resulting in penetration in the electrode area ； 3》Zirconium tube aging; Solution: Replace the zirconium tube. 4》The furnace temperature is too low, resulting in excessive internal resistance in the zirconium tube. The reason for no indication from the instrument is: 1》The signal output circuit is open-circuited ； 2》Open circuit in the porous platinum electrode of the zirconium tube ； 3》The electric furnace is used for heating; the instrument indicates full scale at any setting: 1》The electrode signals are reversed ； 2》The zirconium tube electrode falls off, or the platinum electrode evaporates after long-term use. Header pointer jitter: 1) Excessive amplification gain of the amplifier; 2) Poor wiring connections; 3) Poor contact in connectors. Large fluctuations in the output signal: 1) Incorrect sampling point location; 2) Unstable combustion system; 3) Water present in the sample gas, leading to oxidation within the zirconium tube. How to determine the quality of zirconium tubes: At room temperature, the resistance of zirconium tubes is infinite. When the instrument is operating at high temperatures and dry air is passed through it, its internal resistance, as measured with a multimeter, should be less than 50 ohms. If the resistance value is high, the measurement error will increase ； If the internal resistance is very high or infinite, it indicates that the zirconium tube is broken or the platinum electrode has fallen off; the zirconium tube is damaged and cannot be used