1、 Purpose
specificationZirconia oxygen analyzerThe calibration operation ensures that the analyzer operates normally and the detection data is accurate and reliable.
2、 Scope of application
Applicable toZirconia oxygen analyzerRegular calibration and daily calibration.
3、 Verification conditions
Standard gas
Air: Oxygen content 20.6% (used for air calibration).
Zero point calibration gas: Balanced nitrogen gas with 0.5% or 5% oxygen content (used for zero point calibration).
Range standard gas: selected according to the analyzer range, usually 90% of the full range (such as 18% or 20% oxygen content).
environmental conditions
Temperature: 15-35 ℃ (to avoid extreme temperature affecting sensor stability).
Humidity: ≤ 85% RH (to prevent circuit short circuits or sensor damage caused by high humidity).
Pressure: close to standard atmospheric pressure (to avoid pressure fluctuations affecting measurement results).
Instrument Status
The analyzer should be in a stable working state without any errors or warning alarm messages.
The sensor (zirconium head) shows no signs of damage or corrosion, and the surface is clean and free of dirt.
4、 Verification steps
preparation
Check the equipment: Confirm that the power and gas connections of the analyzer are normal, and that the display and control buttons are functioning properly.
Prepare consumables: standard gas (air, zero point standard gas, range standard gas), dry nitrogen gas (for blowing), gas flow meter, calibration tubing, and seals.
Software upgrade: Ensure that the analyzer software is at the latest version for optimal performance and calibration functionality.
system cleaning
Thoroughly clean the gas path system of the analyzer with dry nitrogen to remove dust, moisture, and other pollutants, and prevent interference with calibration results.
Air calibration (zero calibration)
Operation steps:
Press the 'Menu Key', enter the user password to enter user mode, and select 'Air Calibration'.
Introduce air on both sides of the analyzer sensor (or pump air in online operation), with a flow rate controlled between 500-600ml/min.
After the measured value stabilizes, record the reading. If the deviation between the reading and the standard value of 20.6% is ≤ 2%, no adjustment is required; If the deviation is greater than 2%, use the "↑" or "↓" keys to adjust to 20.6%, and press the "confirm" key twice in a row to save the result.
Calibration of standard gas (range calibration)
Operation steps:
Adjust the standard gas flow rate to 500-600ml/min, remove the sealing screw of the analyzer's standard gas inlet, and connect it to the range standard gas pipeline.
Connect the standard gas and press the "confirm" button to enter calibration mode. Enter the nominal value of the standard gas (such as 18% or 20%).
After the measured value stabilizes, record the reading. If the deviation between the reading and the nominal value is within the allowable range (usually ≤ 1%), save the result; If the deviation exceeds the limit, adjust the range adjuster until it meets the requirements.
cross-check
Perform cross validation using standard gases of different concentrations (such as 5%, 10%, 15% oxygen content) to ensure the accuracy of the analyzer within different concentration ranges.
Data recording and analysis
Record all data during the calibration process, including environmental conditions, zero calibration values, range calibration values, and cross check results.
Use calibration software or professional tools to analyze data, generate calibration curves and reports.
5、 Maintenance after verification
Sealed storage: After calibration is completed, immediately tighten the standard gas inlet screw to maintain good sealing of the gas path.
Record archiving: Properly preserve calibration records, including calibration dates, standard gas information, calibration curves, and adjustment data, for subsequent verification and quality control.
Regular maintenance: According to the frequency of use and environmental conditions, regularly clean the sensors, replace desiccants and filters to ensure the long-term stable operation of the analyzer.
6、 Precautions
Safety first: Pay attention to ventilation when handling standard gases to avoid the risk of suffocation or explosion caused by gas leakage.
Avoid pollution: During the calibration process, prevent dust, moisture, and oil from entering the gas path system, which may affect the sensor's lifespan and measurement accuracy.
Calibration frequency: It is recommended to conduct a comprehensive calibration every 3 months. If the usage environment is harsh or the measurement requirements are strict, the calibration cycle should be shortened.
Cold machine operation: For newly installed or long-term disused analyzers, the indication may be unstable within 24 hours of cold machine operation. It is recommended to calibrate after one day of operation.
Zero point gas selection: Avoid using pure nitrogen gas (N ₂) as the zero point gas, usually choose 10% of the full range as the zero point, and the range gas is 90% of the full range.