Here is a set of preventive measures for unstable pressure differential readings of the air shower transfer window that can be directly implemented on-site, are simple and easy to remember, and are suitable for training, posting on the wall, and creating an SOP:
Unstable pressure differential readings of the pressure differential meter
Prevention measures
1. Daily operation prevention (most critical and effective)
Do not open both doors simultaneously
Always ensure the electronic interlock is normal, prevent direct connection between the clean area and the non-clean area, and avoid chaotic airflow and sudden pressure differences.
Close the door tightly
After each use, confirm that the door body is completely closed, and the sealing strip is seamlessly attached without any gaps.
Do not block the nozzle or the air duct with items
Place the transfer materials centrally, do not block the air shower nozzle or the return air filter, to ensure stable airflow.
Do not open the door or disturb during the air shower operation
Do not touch the door or move items during the air shower, to avoid sudden changes in pressure.
2. Daily maintenance prevention of pressure differential meter and pressure guiding tube
Calibrate the zero position once a month
The pointer must return to zero when the power is cut off and the machine stops to prevent drift and random reading jumps.
Do not bend, press, or block the pressure guiding tube
Regularly inspect the pipeline, straighten the bends, and blow clean air once a month to prevent dust or water from blocking.
Regularly tighten the joints
Prevent loose air leakage and cause unstable readings.
Do not randomly disassemble, collide, or damage the pressure differential meter
Avoid damaging the internal mechanism.
3. Prevention of filtration system (stabilize the airflow from the source)
Clean / inspect the primary filter weekly
Blockage of the primary filter → unstable air volume → pressure differential must jump.
Regularly check the sealing of the high-efficiency filter
Prevent air leakage and sudden changes in resistance.
Replace the high-efficiency filter promptly when reaching the pressure differential threshold
Do not use beyond the expiration date to avoid long-term overloading of the fan and fluctuation of air volume.
4. Prevention of door body and seal
Regularly inspect the door seal
Replace immediately if aging, deformed, or hardening to ensure consistent sealing.
Regularly tighten the hinges and locks
Prevent the door from not closing tightly and leaking air.
Regularly test the interlock function
Ensure that when one side of the door is opened, the other side is absolutely locked.
5. Prevention of fan and electrical components
Listen for sounds, observe vibration
Address any abnormal sounds or large vibrations promptly to avoid sudden changes in air volume.
Ensure stable power supply
Unstable voltage will directly cause pressure differential fluctuations.
6. Management prevention (the simplest but most easily overlooked)
Establish a pressure differential record sheet
Record daily, detect abnormalities early, and handle them promptly.
Uniformly train the operators
Clarify: standard actions for opening the door, placing items, air shower, and closing the door.
Do not allow non-professionals to randomly disassemble, adjust, or modify
Do not privately change parameters or dismantle the air duct.