NEN EN 779 : 2012

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
5 Requirements
6 Classification
7 Test rig and equipment
   7.1 Test conditions
   7.2 Test rig
   7.3 Aerosol generation
   7.4 Aerosol sampling system
   7.5 Flow measurement
   7.6 Particle counter
   7.7 Differential pressure measuring equipment
   7.8 Dust feeder
8 Qualification of test rig and apparatus
   8.1 Air velocity uniformity in the test duct
   8.2 Aerosol uniformity in the test duct
   8.3 Particle counter sizing accuracy
   8.4 Particle counter zero test
   8.5 Particle counter overload test
   8.6 100 % efficiency test
   8.7 Zero % efficiency test
   8.8 Aerosol generator response time
   8.9 Pressure equipment calibration
   8.10 Pressure drop checking
   8.11 Dust feeder air flow rate
   8.12 Neutraliser
   8.13 Summary of qualification requirements
   8.14 Apparatus maintenance
9 Test materials
   9.1 Test air - cleanliness, temperature and humidity
   9.2 Test aerosol
   9.3 Loading dust
   9.4 Final filter
10 Test procedure
   10.1 Preparation of filter to be tested
   10.2 Initial pressure drop
   10.3 Initial efficiency
   10.4 Dust loading
11 Uncertainty calculation of the test results
12 Reporting
   12.1 General
   12.2 Summary
   12.3 Efficiency
   12.4 Pressure drop and air flow rate
   12.5 Arrestance and dust holding capacity
   12.6 Marking
Annex A (normative) Electrostatic discharging procedure
        A.1 General
        A.2 Test method for discharging of filter material
        A.3 Expression of results
Annex B (informative) Shedding from filters
        B.1 General
        B.2 Shedding
        B.3 Testing
        B.4 References
Annex C (informative) Commentary
        C.1 General
        C.2 Classification
        C.3 Test
        C.4 Filtration characteristics
Annex D (informative) Pressure drop calculation
Annex E (informative) Example of a completed test report
        E.1 Example of test reports
        E.2 Example of calculations
        E.3 Final results at 450 MPa
Bibliography

Contains requirements to be met by particulate air filters. Describes testing methods and the test rig for measuring the filter performance. Coverage includes definitions, materials and marking.