Professional Services
PAO Leak Test
Product Overview
PAO (Poly-Alpha-Olefin) leak testing is the standard method for on-site integrity and leak detection of HEPA / ULPA high-efficiency air filters in cleanrooms. In accordance with IEST-RP-CC034, ISO 14644-3, and US Federal Standard FED-STD-209E, Baisheng Tech uses an aerosol generator to uniformly produce PAO standard oil aerosol upstream of the filter, then uses an aerosol photometer to comprehensively scan the downstream discharge face and the junction between the filter and the frame. This determines whether the filter medium is damaged, whether frame adhesion is leaking, and whether installation sealing is secure, ensuring cleanroom cleanliness classification and GMP validation requirements.
Features & Specifications
| Item | Specification / Method |
|---|---|
| Test standard | IEST-RP-CC034 / ISO 14644-3 / FED-STD-209E |
| Applicable filters | HEPA (H13/H14), ULPA (U15 and above) |
| Test aerosol | PAO (Poly-Alpha-Olefin) * FDA food-grade compliant |
| Upstream concentration | 10 ~ 100 μg/L |
| Scan speed | ≤ 50 mm/s |
| Probe distance from filter | ≤ 25.4 mm (1 inch) |
| Sampling flow | 28.3 L/min (1 CFM) ± 10% |
| Acceptance criteria | Downstream penetration ≤ 0.01% (H14) / ≤ 0.005% (ULPA) |
| Report contents | Test report + leak location diagram + certification label |
Detailed Description
## Service Overview
Baisheng Tech provides on-site integrity testing (PAO Leak Test) services for HEPA / ULPA high-efficiency filters in cleanrooms, covering pre-test airflow/velocity verification, aerosol uniformity validation, full-area leak scanning, leak repair recommendations, certification labeling, and formal validation reports. Widely applied in semiconductor, optoelectronics, biomedical, pharmaceutical GMP, and medical facility clean environments.
## Test Principles
- **Upstream injection**: Cold / thermal aerosol generators produce PAO droplet aerosol with particle size approximately 0.3 μm upstream of the filter
- **Downstream scanning**: An aerosol photometer (Photometer) scans comprehensively in an S-shaped trajectory at a distance of ≤ 25.4 mm from the downstream discharge face
- **Penetration calculation**: Real-time comparison of upstream/downstream concentration ratio, calculating local penetration to determine leaks
- **Frame inspection**: Focused scanning on filter frames, adhesive joints, gaskets, and installation gaps to identify installation leaks
## Test Procedure
1. **Pre-test verification**: Inspect filter model, dimensions, installation status, and return air system operation
2. **Velocity measurement**: Measure average discharge face velocity per ISO 14644-3, confirming rated range
3. **Upstream concentration establishment**: After PAO injection, sample upstream to confirm 10~100 μg/L concentration with uniformity ≤ ±15%
4. **Downstream leak scanning**: Comprehensively scan filter discharge face and surrounding joints at ≤ 50 mm/s
5. **Leak marking**: Positions exceeding penetration limits are labeled and reported to construction team for repair
6. **Re-test verification**: Rescan after repair until fully compliant
7. **Report delivery**: Provide test report, leak location diagram, certification label, and calibration traceability documents
## Acceptance Criteria
## Test Principles
- **Upstream injection**: Cold / thermal aerosol generators produce PAO droplet aerosol with particle size approximately 0.3 μm upstream of the filter
- **Downstream scanning**: An aerosol photometer (Photometer) scans comprehensively in an S-shaped trajectory at a distance of ≤ 25.4 mm from the downstream discharge face
- **Penetration calculation**: Real-time comparison of upstream/downstream concentration ratio, calculating local penetration to determine leaks
- **Frame inspection**: Focused scanning on filter frames, adhesive joints, gaskets, and installation gaps to identify installation leaks
## Test Procedure
1. **Pre-test verification**: Inspect filter model, dimensions, installation status, and return air system operation
2. **Velocity measurement**: Measure average discharge face velocity per ISO 14644-3, confirming rated range
3. **Upstream concentration establishment**: After PAO injection, sample upstream to confirm 10~100 μg/L concentration with uniformity ≤ ±15%
4. **Downstream leak scanning**: Comprehensively scan filter discharge face and surrounding joints at ≤ 50 mm/s
5. **Leak marking**: Positions exceeding penetration limits are labeled and reported to construction team for repair
6. **Re-test verification**: Rescan after repair until fully compliant
7. **Report delivery**: Provide test report, leak location diagram, certification label, and calibration traceability documents
## Acceptance Criteria| Filter Class | Overall Efficiency | Local Penetration Limit (PAO Scan) |
|---|---|---|
| HEPA H13 | ≥ 99.95% | ≤ 0.01% |
| HEPA H14 | ≥ 99.995% | ≤ 0.01% |
| ULPA U15 | ≥ 99.9995% | ≤ 0.005% |
| ULPA U16 | ≥ 99.99995% | ≤ 0.005% |
* Any instantaneous reading exceeding the limit at any point during scanning is determined to be a leak and must be repaired on-site or the filter replaced and re-tested.
## Instruments Used
- **Aerosol Photometer**: ATI TDA-2i or equivalent, dynamic range 0 ~ 100 μg/L, resolution 0.001%
- **PAO Generator**: Cold (Laskin Nozzle) or thermal, selected by filter area
- **Particle Counter**: Sampling flow 2.83 L/min (0.1 CFM), particle size channels 0.3 / 0.5 / 1 / 3 / 5 μm
- **Anemometer / Air Capture Hood**: Measures filter discharge face velocity and total airflow
## Applications
- Semiconductor, TFT-LCD, OLED cleanrooms Class 1 ~ Class 10,000
- Biotech/pharmaceutical GMP A / B / C / D grade aseptic areas
- Hospital operating rooms, ICU, isolation wards, negative pressure wards
- Biological safety cabinets (BSC), laminar flow workbenches, glove boxes
- Pharmaceutical filling lines, aseptic filling lines, RABS / Isolator
- Nuclear facility HEPA filtration systems, AMC exhaust treatment systems
## Service Commitment
- Test personnel certified with IEST / ISO 14644 training
- Instruments calibrated annually by OEM with traceability documents
- Bilingual (Chinese/English) test reports provided
- Island-wide on-site service including night and holiday engineering coordination
◎ Test standards: IEST-RP-CC034 / ISO 14644-3 / FED-STD-209E ◎ Report format: PDF + physical signed copy ◎ Customized test programs per customer SOP welcomed
