Number of views: 2799 Author: Aili Industry Release time: 2027-05-19 Source: Ai Li Industrial
Can particle counting and online monitoring replace ULPA scanning leak detection?
ULPA filter testing, particle counting or online monitoring cannot automatically replace scanning leak detection. In The environmental concentration reflects the state of particles at the measuring point, and scanning leak detection is used to locate local integrity problems in the filter element and installation system. Online monitoring tells you 'how many particles are there at this moment', and scanning leak detection tells you 'where is this leak point'. The former is point measurement, and the latter is area scanning; the former finds abnormalities, and the latter locates the cause. The two solve different problems and cannot be substituted for each other. Aili Industry isFFU fan filter unit andIn the control scheme of the fan filter unit at the EFU equipment end , online monitoring data and leak detection records are managed separately: monitoring data is used for trend warning, leak detection records are used for integrity verification, and supportingThe FFU computer group control system can present two types of data at the same time, but it will not replace leak detection conclusions with monitoring readings.
1. Clear measurement objects: point measurement and surface scanning solve different problems
Online sensors monitor limited locations and time periods, and readings are also affected by airflow, activity and sampling; it may not be able to capture small local leaks.
The sampling port of an online particle sensor is usually arranged at a fixed position, and the particle concentration near that position is monitored. If the leak point is far away from the sampling port, the sensor reading may still be normal even if there is a local leak. Scanning leak detection means that the probe scans point by point along the filter surface and sealing surface to find the location of local leaks. Aili Industry isWhen the ULPA ultra-high-efficiency filter is delivered, the leak detection method and coverage of the model can be explained, and the project party can arrange the integrity verification accordingly, instead of using environmental monitoring data to infer the status of the filter element. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。
2. Let different tests complement each other: use trends to find anomalies, and then check for completeness
Use trends to identify anomalies and then check air volume, contamination sources, and installation integrity as needed. Just because the primary particle reading is low does not mean that the leak detection specified in the project can be omitted.
The advantage of online monitoring lies in continuity and trend: it can find that the particle concentration in a certain area slowly rises over several days or weeks, indicating possible filter dust accumulation, seal aging or changes in pollution sources. After an abnormality is discovered, use scanning leak detection to confirm the integrity and air volume testing to confirm the working point to locate the cause. Aili Industry isThe FFU computer group control system associates online monitoring data, air volume data and leak detection records by points. When the trend is abnormal, the complete data of the corresponding points can be quickly retrieved to provide direction for investigation. For the cooperation method of monitoring and leak detection, please refer toHEPA FAQs and Selection Guide。
3. Alternative solutions must have applicable basis: what to do when the structure cannot be scanned
If the structure cannot be scanned, the capability and coverage of the method should be evaluated according to the project and specifications, and the limitations should be explained to avoid renaming ordinary online monitoring as integrity verification.
It is true that the internal structure of some equipment is difficult to conduct routine scanning and leak detection. In this case, other integrity verification methods can be considered, but the applicability and coverage of the method need to be explained and clearly recorded in the project documents. Aili Industry isNon-standard ULPA filters andIn space-constrained projects such as ultra-thin EFU , the feasibility of the leak detection method will be evaluated based on the equipment structure. If the conventional scanning path is limited, solutions can be proposed from the aspects of detection interface reservation, partial disassembly or alternative verification methods, rather than using online monitoring data as a complete conclusion. For restrictions on internal testing conditions of the equipment, please refer toEFU FAQ and technical support。
4. When the measuring point is far away from the frame leakage point, the count may still be low.
Counts may still be low when measuring points are far away from frame leaks, and the interface should be confirmed by specifying integrity testing rather than just moving the sensor to look for good results. The particle diffusion of local leaks is affected by the direction of air flow. If the sampling port is located upwind of the leak or in the airflow dead zone, the readings may not reflect the existence of the leak.
Aili Industry isThe leak detection of ULPA ultra-high efficiency filter covers the whole area according to the filter surface and sealing surface, and does not rely on a single measuring point to judge the integrity;The online monitoring point layout of the FFU computer group control system can be designed based on the air flow direction and process layout, but the optimization of monitoring points cannot replace the coverage requirements of installation leak detection. For the relationship between monitoring point layout and leak detection coverage, please refer toULPA ultra-high efficiency filter FAQ and selection guide。
5. Related questions and answers
Does the increase in online particle number prove that ULPA is broken?
No, reasons such as personnel, process contamination, air flow and instruments should also be investigated.
If the environmental monitoring data is qualified, do I still need to do installation leak detection?
need. Environmental monitoring reflects the concentration of the measuring point, and installation leak detection verifies the integrity of the seal. The two are verifications at different levels.
What should I do if the structure cannot be scanned for leaks?
The applicability and coverage of alternative methods should be evaluated according to projects and specifications, and limitations should be explained. Online monitoring data cannot be directly used as a conclusion on completeness.
6. Related articles
ULPA ultra-high efficiency filter FAQ and selection guide
FFU computer group control system
7. Key points for selection and acceptance inspection
Check items |
Check the key points |
|---|---|
Measurement object |
Different uses of point monitoring and area scanning |
Monitoring coverage |
Relationship between sampling point location and air flow direction |
Data coordination |
The connection between trend warning and integrity detection |
alternative |
Applicable basis and limitations when the structure is restricted |
Verify independence |
Monitoring data does not replace installation leak detection conclusions |
8. Product matching and technical support from Aili Industrial
Aili Industry isFFU fan filter unit andthe fan filter unit at the EFU equipment end , online monitoring data and leak detection records are managed separately.In the control scheme of The FFU computer group control system simultaneously displays monitoring data, air volume data and leak detection records and correlates them by point. When the trend is abnormal, the complete data of the corresponding point can be retrieved.ULPA ultra-high-efficiency filter leak detection covers the entire filter surface and sealing surface, and does not rely on a single measuring point to determine the integrity;Non-standard ULPA filters andFor space-constrained projects such as ultra-thin EFU , the feasibility of the leak detection method can be evaluated based on the equipment structure, and solutions can be proposed from the detection interface reservation, partial disassembly, or alternative verification methods. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.
