1、 Key points of daily maintenance
Appearance and pneumatic inspection
Daily inspection: visually inspect the appearance of the instrument to confirm that there are no leaks, damages, or abnormal noises; Check if the gas path connection is tight to avoid gas leakage caused by looseness.
Weekly maintenance: Use high-purity nitrogen to blow the gas path to prevent residue accumulation; Clean the injection port and detector interface to ensure smooth gas flow.
Monthly maintenance: replace filter elements, check the inlet pressure of process air and instrument air, clean the analyzer and related equipment, and perform system calibration.
Key component maintenance
Electromagnetic valve: Clean the normally closed electromagnetic valve every 6 months to prevent incomplete closure caused by internal spring failure or foreign object blockage.
Sealing components: Check the condition of the sealing ring every 3 months, replace it promptly if aging or damage is found, clean the sealing groove during replacement, and ensure that it is installed in place.
Heating element: Check the working status of the heating element every month to ensure that the temperature control accuracy is within ± 0.5 ℃; Use an infrared thermometer to calibrate the temperature of the heating system every six months.
Environment and Power Management
Temperature control: Ensure that the temperature of the medium and the working temperature of the detection room meet the requirements of the instrument, and avoid temperature affecting measurement accuracy.
Power stability: Use UPS power supply to prevent damage to the instrument caused by grid fluctuations; The connection between the power line and the signal line should be correct to avoid electromagnetic interference.
Data calibration and recording
Regular calibration: Monthly comparison and analysis with laboratory data to ensure the accuracy of online analyzers; Perform full calibration every six months to calibrate quantitative correction factors and standard curves.
Record management: Establish a comprehensive maintenance record system to record in detail the content of each maintenance, the problems discovered, and the results of their handling, providing a basis for preventive maintenance.
2、 Common faults and troubleshooting methods
The instrument cannot start or displays abnormally
Fault phenomenon: The display screen does not light up, there is no text, or the data is abnormal.
Exclusion steps:
Check if the power cord is securely plugged in and if the fuse is intact.
Re plug the five wire plug of the circuit board and adjust the potentiometer of the display screen circuit board to adjust the contrast.
Check for loose connections in the wiring and replace the key film if necessary.
Inaccurate or fluctuating measurement values
Fault phenomenon: The measured value is higher/lower than the scale set by the operator, or the data fluctuates violently.
Exclusion steps:
Check the purity and flow rate of the carrier gas to ensure stability, and confirm that the temperature control of the heating system is normal.
Clean the detector. If the problem persists, it may be contamination of the detector and requires professional cleaning.
Check if the injection system is leaking, confirm if the injection needle is blocked, and replace the chromatography column if necessary.
Equipment automatic fire extinguishing or ignition failure
Fault phenomenon: The burner cannot ignite or goes out after ignition.
Exclusion steps:
Check if the solenoid valve of the gas pipeline is faulty.
Confirm whether the coil of the pulse ignition device is burnt out.
Check the internal resistance of the oxygen content sensor battery.
Residual oxygen content exceeds the normal range
Fault phenomenon: The residual oxygen content exceeds the working range of 1.5% -6%.
Exclusion steps:
Measure the internal resistance of the oxygen cell (method: open the black cover of the sensor, measure the two ends of the battery with a multimeter in ohms range, and take the average value).
If the internal resistance is abnormal or the zirconium tube is broken, the zirconia sensor needs to be replaced.
Leakage or blockage of gas path
Fault phenomenon: Abnormal air pressure, unstable flow or inability to measure.
Exclusion steps:
Use a leak detector to inspect all fittings of the flow pressure regulating panel and the pressure regulator section of the gas cylinder, and correct leaks using the bubble method.
Turn the clockwise knob to turn off the carrier gas and observe the pressure decay rate. If the pressure cannot be maintained constant, check the valve and tighten it.
Clean the calibration gas and sample gas paths to ensure no residue blockage.
3、 Preventive maintenance recommendations
Develop maintenance plan: Based on equipment usage frequency and environmental conditions, develop monthly, quarterly, and annual maintenance plans, clarify maintenance content and responsible persons.
Spare parts management: Reserve commonly used spare parts to ensure quick replacement in case of malfunction.
Personnel training: Regularly provide maintenance training to operators to improve their ability to identify and handle faults.
Environmental control: Keep the working environment of the instrument dry and clean, and avoid dust and corrosive gases from affecting the service life of the equipment.