The daily operation of laminar flow sampling vehicles

Laminar flow sampling vehicles are important equipment used to ensure a clean sampling environment and avoid contamination. Their daily operation norms are crucial for guaranteeing the accuracy of sampling and the normal operation of the equipment. The following are the daily operation procedures and precautions for laminar flow sampling vehicles:
I. Preparations Before Operation
1. Equipment inspection
Visual inspection: Check the vehicle body for any obvious damage or loose parts, and ensure that the control panel buttons and display screen are functioning properly.
Filter status: Check whether the primary filter (generally washable type) has accumulated too much dust. If obvious dust is visible on the surface, it needs to be cleaned or replaced in time. High-efficiency filters (HEPA) need to be determined whether they need to be replaced through a differential pressure gauge (when the differential pressure exceeds the rated value, it indicates a decrease in efficiency).
Power supply and wiring: Make sure the power cord is undamaged, the plug is securely connected, and the device is connected to a stable power source (usually 220V AC).
2. Environmental preparation
Place the sampling vehicle on flat ground, away from areas with significant air flow disturbances such as doors, Windows, and ventilation openings. Ensure that there are no miscellaneous items piled up within 1-2 meters around to avoid affecting the laminar flow effect.
Before starting the equipment, wipe the surface, inner walls, and air outlets of the operation console with 75% alcohol for initial disinfection.
Ii. Startup and Operation
1. Startup process
Connect the power supply, press the power switch on the control panel, and the equipment will start self-checking (the display screen may show initialization information, such as fan speed, pressure difference value, etc.).
After the self-check is completed, select the "Laminar Flow Mode" (some devices have a "normal/High Efficiency" mode switch), start the fan, and observe whether the airflow at the outlet is uniform (this can be done through ribbon or smoke tests; the airflow should flow steadily in a straight line downward/forward).
2. Parameter Settings
Adjust the wind speed according to the sampling requirements (generally, the laminar flow wind speed should be maintained at 0.3-0.5m/s; please refer to the equipment manual for specific details), and set the target value through the "+/-" keys on the panel.
If the equipment has a timing function, the running time can be set (for example, start the machine 30 minutes in advance before sampling to ensure adequate air purification).
3. Operation check
During operation, monitor the noise of the equipment. If any abnormal sounds occur (such as fan jamming or resonance), stop the machine immediately for inspection.
Observe whether the reading of the differential pressure gauge is within the normal range (the differential pressure of the primary filter is generally ≤50Pa, and that of the high-efficiency filter is ≤250Pa). If it exceeds the limit, record it in time and handle it.
Iii. Sampling Operation Specifications
1. Item placement
Sampling tools (such as sampling bottles, test tubes, tweezers, etc.) need to be sterilized in advance and placed in the center of the operation table to avoid blocking the air outlet.
Items should be placed neatly with a spacing of no less than 5cm to ensure unobstructed airflow and avoid stacking too many items on the operating table.
2. Sampling process
Operators must wear clean suits and gloves, extend their arms from the side of the operation table, and move gently to avoid violent shaking that may cause vortices.
When sampling, place the sample directly beneath the laminar flow and follow the standard operating procedures (such as aseptic operation) for sampling. Avoid having hands or other non-sterile items come into contact with the sample.
If tools need to be changed during the sampling process, they should be wiped with alcohol before use to avoid contamination.
3. Exception handling
If the laminar flow is suddenly weakened or interrupted, stop sampling immediately, turn off the equipment, and check whether the filter is clogged and whether the fan is faulty.
If samples are accidentally knocked over or liquids spill during operation, they should be immediately cleaned up with absorbent paper, and the contaminated area should be repeatedly disinfected with alcohol. If necessary, the machine should be stopped for cleaning.
Iv. Shutdown and Maintenance
1. Shutdown steps
After sampling is completed, continue to run the equipment for 10 to 15 minutes to expel the remaining aerosols or particles on the operation table.
Turn off the laminar flow mode, press the power switch to shut down the machine, and unplug the power cord (when the machine is out of service for a long time).
2. Daily cleaning
Surface cleaning: Wipe the operation console, inner walls, and outer shell with neutral detergent, then disinfect with 75% alcohol. Avoid using corrosive detergents.
Filter cleaning: The primary filter should be cleaned once a week (rinse with clean water until there is no visible dust, dry, and then reinstall). High-efficiency filters are generally inspected for efficiency once a year. If the efficiency drops below 85% or the pressure difference exceeds the limit, they must be replaced (operated by professionals).
3. Recording and Maintenance
Fill in the "Laminar Flow Sampling Vehicle Usage Record Form", recording the startup time, operating duration, filter status, abnormal conditions, and handling measures.
Check the tightness of the fan belt (if any) once a month to ensure stable rotational speed. Conduct a comprehensive performance verification of the equipment once every quarter (such as wind speed and dust particle count detection).
V. Safety Precautions
Do not touch the fan or disassemble the internal components when the equipment is in operation to avoid electric shock or mechanical injury.
If the sampling involves toxic, harmful, or biohazardous substances, it is necessary to confirm in advance whether the equipment has the corresponding protection level (such as biosafety laminar flow cabinets) and strictly adhere to relevant safety regulations.
Before long-term disuse, the equipment must be thoroughly cleaned, covered with a dust cover, and stored in a dry and well-ventilated place.
By standardizing daily operations and maintenance, laminar flow sampling vehicles can always maintain high purification capabilities, ensuring the cleanliness of the sampling environment and providing a guarantee for the accuracy of experimental or test results. If there are special models of equipment, the operation details should be adjusted by their instructions.