Overview
EN ISO 29463-4:2018 (CEN adoption of ISO 29463-4:2011) defines the scan method - the reference test procedure for determining leakage of high-efficiency filter elements. It applies to filter classes ISO 35 H to ISO 75 U and describes alternate normative methods (oil thread leak test, aerosol photometer scan, and PSL solid-aerosol leak test) where appropriate. This part is intended to be used in conjunction with ISO 29463-1, -2, -3 and -5 for a complete filter test and classification framework.
Key topics and requirements
- Reference scan method: Step-by-step leakage detection by scanning the downstream side of a filter element to identify and quantify local penetration/leaks.
- Scope of application: Filters from ISO 35 H up to ISO 75 U; alternate methods limited to lower-efficiency HEPA ranges (oil thread and photometer tests applicable to ISO 35 H–ISO 45 H).
- Test apparatus and set-up: Requirements for test duct, scanning assembly, aerosol generation and measurement instruments (optical particle counters, condensation nucleus counters, aerosol photometers) and their arrangement.
- Test procedure: Preparatory checks, aerosol generator start-up, sample preparation, scanning/testing routines, sampling durations and reporting of results.
- Normative and informative annexes: Includes oil thread leak test (Annex A), photometer filter scan (Annex B), PSL solid-aerosol leak test (Annex E), methods for determining test parameters (Annex C), worked examples (Annex D), and other guidance (Annices F, G).
- Reporting & maintenance: Required test report items and guidance for maintenance/inspection of test apparatus.
Applications and who uses it
EN ISO 29463-4:2018 is used by:
- Filter manufacturers for type testing and quality control of HEPA/ULPA elements.
- Independent test laboratories performing leakage certification and diagnostic scans.
- Cleanroom and HVAC engineers verifying installed filter integrity in critical environments (pharma, semiconductor, healthcare).
- Facility managers and procurement teams specifying acceptance and performance criteria for high-efficiency filters.
- Regulators and auditors requiring standardized leakage test evidence.
Practical uses include locating local leaks, validating element assembly and sealing, acceptance testing after shipping/installation, and compliance testing for cleanroom or critical-process filtration.
Related standards
- ISO 29463-1, -2, -3, -5 - companion parts covering classification, aerosol generation, media testing and whole-element test methods.
- ISO 29464 - terminology for cleaning equipment for air and other gases.
- ISO 5167-1 - referenced for fluid flow measurement principles used in test setups.
Keywords: EN ISO 29463-4:2018, ISO 29463-4, scan method, filter leakage test, HEPA, ULPA, aerosol photometer, oil thread leak test, PSL aerosol, high-efficiency filters.
