T/CRAAS 439.4-2022 General Ventilation Filter - Part 4: Determining Minimum Path Effect Efficiency for Eliminating Electrostatic Charges

Scope

Main technical content: This part of the T/CRAAS 439 series standard specifies an anti-static method for determining the minimum efficiency of filters. The standard provides requirements for the tested filters and anti-static cabinets, and gives the test procedures. This standard needs to be used in conjunction with T/CRAAS 439.1, T/CRAAS 439.2, and T/CRAAS 439.3. The test bench used in this standard is for tested filters with a nominal cross-sectional size of 610 mm × 610 mm. The T/CRAAS 439 standard (all parts) applies to general ventilation filters that meet the test procedures specified in this series standard and have an ePM1 efficiency not higher than 99% and an ePM10 efficiency not lower than 20%. Note: The lower limit of ePM10 efficiency for filters specified in this standard is 20%, because when the efficiency is lower than this, it is difficult to ensure the statistical validity of the test results obtained by this standard. For the measurement of filter efficiency in other particle size ranges, other test methods are used, see T/CRAA 431. This standard is not applicable to filter elements used in portable indoor air purifiers. The test results of filter performance obtained according to this series standard cannot be used to quantitatively predict the filter efficiency and service life of the tested filters under actual operating conditions. The filters are graded according to their counting efficiency in the range of 0.3 μm to 10 μm, and other standards that focus on whether the filter material has an electrostatic mechanism can refer to this standard for testing.

Development Information

Same series standard

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