The maintenance and validation methods and key points of the optical oxygen pressure multifunctional analyzer are as follows:
1、 Daily cleaning and pollution prevention
Shell cleaning
Wipe the instrument casing with a clean soft cloth, avoiding the use of corrosive cleaning agents (such as diluted with alcohol) to prevent damage to the surface coating.
Regularly clean the surface dust of the sensor probe to prevent blockage or sensitivity decrease. If in contact with oil stains or chemicals, immediately use specialized cleaning agents for treatment.
Maintenance of pneumatic system
Keep the air path clean and regularly replace filters (such as stainless steel powder metallurgy filters, ceramic filters) to avoid blockage by scale and sediment.
Simplify the gas path structure, remove residual sample gas from dead corners of pipelines, and prevent pollutants from interfering with measurements.
moisture and mold proof
When stored for a long time, place the instrument in a dry and ventilated environment, avoiding direct sunlight and moisture.
Regularly check the dry silicone gel, and replace it promptly if it changes color to prevent internal components from getting damp.
2、 Special maintenance of sensors
status check
Regularly inspect the sensor surface for stains, oxides, or mechanical damage. If contamination is found, clean with mild cleaning solution and air dry.
Avoid direct impact of high concentration gases on the sensor to prevent shortened lifespan.
Optical sensor calibration
Zero point calibration: Use pure nitrogen gas (≥ 99.99%) or zero point gas, pass through the sensor for 10 minutes, and confirm the calibration value after the reading stabilizes.
Range calibration: Using a known concentration of oxygen standard gas (such as O ₂ in 20.0% nitrogen), repeat the zero calibration steps to ensure accurate range.
Two point calibration: For optical sensors, it is necessary to calibrate both the zero phase angle (phi0) and the saturation air saturation value (phi100) simultaneously, especially after replacing the optical cap.
Process calibration: In fermentation or cell culture, after sterilization, adjust the measured values to the full degree value (such as 100% air) with a fixed air flow rate to ensure stable process parameters.
Electrochemical sensor maintenance
Regularly check whether the temperature and pressure of the sampling valve meet the requirements, and adjust them through a pressure reducing valve.
Close the pressure reducing valve at the scheduled time and slowly switch the gas to avoid pressure shock and damage to precision components.
3、 Power and electrical system inspection
Power cord and plug
Check if the power cord is damaged and if the plug is in good contact to avoid short circuits or leakage.
Keep the power cord ventilated, avoid obstruction or heating, and prevent aging.
battery maintenance
Regularly check the battery level and replace aging batteries (such as lithium batteries) in a timely manner to avoid low battery levels affecting performance.
When stored for a long time, remove the dry battery to prevent leakage and corrosion of the electrode.
4、 Sealing and leakage detection
Seal replacement
When repairing or installing a new probe, it is necessary to replace the seal (such as O-ring) to ensure no leakage.
Sharp tools are prohibited when disassembling sealing components to prevent scratches from affecting the sealing performance.
Gas path leak detection
Regularly inspect all connection points, welding points, and valves, use soapy water to detect leaks, and avoid measurement errors caused by air backflow.
5、 Regular calibration and verification
calibration cycle
Conventional use: Calibrate the sensor every 90 days, reducing it to 30 days for high concentration or corrosive environments.
Comprehensive verification: At least once a year, verify the accuracy of the instrument using standard gases.
Calibration steps
After preheating for 30 minutes, sequentially introduce zero gas and range gas, and compare the displayed value with the nominal value of the standard gas after the reading stabilizes.
If the error exceeds the range, enter calibration mode to modify the value, save it, and then pass zero gas verification. Repeat the operation until the two points match.
Record and Trace
Establish an instrument ledger to record calibration time, results, replacement parts, and other information for easy traceability and management.
6、 Storage and transportation protection
Short term storage
Turn off the power of the instrument and store it in a dry, ventilated, non corrosive gas environment, avoiding direct sunlight.
Long term discontinuation
Remove the battery, seal the instrument in a moisture-proof box, and regularly preheat it with electricity to prevent the electrolytic capacitor from deteriorating.
Transportation protection
Use a dedicated packaging box to secure the instrument to prevent vibration and avoid collision damage to internal components.
7、 Professional maintenance and replacement of accessories
Replacement of vulnerable parts
Regularly replace vulnerable parts such as sensors, filters, seals, etc., and use original accessories to ensure compatibility.
When replacing the sensor, follow the instructions to avoid damaging the wiring or circuit board.
Professional Support
For complex faults or unsolvable problems, contact the manufacturer or professional technicians for repair to avoid further damage caused by misoperation.