ISO/TS 11155-1:2001 道路車両—客室用エアフィルター—パート1：粒子状物質ろ過のテスト | ページ 6

3.1

test air flow rate

volume of air passing through the test duct per unit time, expressed in actual cubic metres per hour (m³/h)

3.2

pressure loss

permanent pressure reduction due to a decrease in the flow energy (velocity head) caused by the filter (in pascals at standard conditions of 23 °C and 101,3 kPa)

3.3

fractional efficiency

E_{f i}

ability of the air filter to remove particles of a specified size, expressed as a percentage

3.4

initial fractional efficiency

fractional efficiency before the collected particles have any measurable effect on the efficiency of the filter under test

Note 1 to entry: The collected particles can affect the measured filter efficiency before enough aerosol is collected to affect the filter pressure loss.

3.5

fractional penetration

P_{f i}

ratio of the concentration of particles of specified size exiting the filter to the concentration of particles of specified size entering the filter, expressed as a percentage

3.6

test dust-holding capacity

mass of test dust collected by the filter at the specified terminal pressure loss and flow rate, expressed in grams

3.7

hydraulic diameter

D_h

3.8

particle counter

aerosol spectrometer

instrument for sizing or counting aerosol particles, or both

3.9

test aerosol

particles suspended in air, used for filter-efficiency or -capacity evaluation

3.10

correlation ratio

R_o

ratio of the number of particles observed at the downstream sampling location to the number of particles at the upstream sampling location when no filter is installed in the test

Note 1 to entry: The method of calculating the correlation ratio is given in annex B.

3.11

log mean diameter

D_{l, i}

3.12

geometric (volume equivalent) diameter

D_{g, i}

diameter of sphere with the same volume as the particle being measured

3.13

optical (equivalent) diameter

D_{o, i}

diameter of a particle of the type used to calibrate an optical sizing instrument that scatters the same amount of light as the particle being measured

Note 1 to entry: Optical diameter depends on the instrument, the type of particle used to calibrate the instrument (usually polystyrene latex spheres), the optical properties of the particle being measured, and the size of the particle.

3.14

aerodynamic (equivalent) diameter

D_{ae, i}

diameter of a sphere of density 1 g/cm³ with the same terminal velocity due to gravitational force in calm air, as the particle being measured

Note 1 to entry: The aerodynamic diameter is used to report results to avoid different diameter measures due to different sizing and counting techniques. Annex F provides additional information about aerodynamic diameter.

3.15

efficiency challenge aerosol

aerosol used to measure the efficiency of a test filter

Note 1 to entry: The concentration is low enough to prevent coincidence-related errors in the particle counters, and does not change the filter efficiency due to loading. The aerosol charge is reduced so that it approximates a Boltzman equilibrium charge distribution. The requirements for the efficiency challenge aerosol are given in 4.2.3 and 4.2.4.

3.16

capacity challenge aerosol

aerosol used to load the filter

Note 1 to entry: The concentration is high enough to allow loading of the filter in a reasonable time, but may be too high to allow the use of typical particle counting instruments. The requirements for the capacity challenge aerosol are given in 4.2.3 and 4.2.4.

3.17

neutralized aerosol

aerosol whose charge distribution is reduced until it provides a Boltzman equilibrium charge distribution

Note 1 to entry: The aerosol is not neutral in the sense that all individual particles are neutral.

Note 2 to entry: It may not be possible to obtain a true Boltzman equilibrium charge distribution in the short time available in a test system. The procedures in annex G are designed to minimize the effect of excess charge arising from the aerosol generation method.