C.3 Macroparticle count C.3.1 Micro

C.3 Macroparticle count

C.3.1 Microscopic measurement of particles collected on filter paper,
see ASTM F312[4]

C.3.2 Cascade impactor, particle collection system where sample is passed at a constant flow rate through a series of orifices of decreasing dimensions; the orifices face the collection surfaces. As fluid velocity increases through each orifice-collector stage, smaller particles are collected for weighing or counting after collection.
The specifications for the cascade impactor are given in Table C.5.

Table C.5 — Specifications for cascade impactor

Item Specification
Measuring limits/range Sampling flow rate as specified
Sensitivity/resolution Sub-micrometer particles can be collected at low pressure
Accuracy Stage “cut-point” accuracy is ≥90 %
Linearity Significant quantity of over-and under-size deposition
Stability 50 %. Cutoff size depends on the sample flow rate
Response time Minutes to days, depending on sample measurement method
Calibration interval 12 months maximum

C.3.3 Discrete-macroparticle counter, instrument capable of counting and sizing (when required) single airborne macroparticles.
The specifications for the discret-macroparticle counter are given in Table C.6.

Table C.6 — Specifications for discrete-macroparticle counter

Item Specification
Measuring limits/range Particle concentration to 1,0 ×106/m3
Sensitivity/resolution 5 μm to 80 μm with 20 % resolution
Uncertainty of measurement Sizing error ±5 % of calibration setting
Linearity Can vary with particle composition or shape
Calibration interval 12 months maximum
Counting efficiency (50 ±20) % at minimum size threshold and (100 ±10) % for particles greater than or equal to 1,5 times the minimum threshold size.

C.3.4 Time-of-flight particle sizing apparatus, discrete-particle counting and sizing apparatus that defines the aerodynamic diameter of particles by measuring the time for a particle to accommodate to a change in air velocity. This is usually done by measuring the particle transit time optically after a fluid stream velocity
change.
The specifications for the time-of-flight particle sizing apparatus are given in Table C.7.

Table C.7 — Specifications for time-of-flight particle sizing apparatus

Item Specification
Measuring limits/range Particle concentration to 1,0 ×107/m3
Sensitivity/resolution 0,5 μm to 20 μm with 20 % resolution
Uncertainty of measurement ±5 % of calibration size setting
Calibration interval 12 months maximum
Counting efficiency (50 ±20) % at minimum size threshold and (100 ±10) % for particles greater than or equal to 1,5 times the minimum threshold size

C.3.5 Piezo-balance impactor, particle collection system where the sample is passed at a constant rate through a series of orifices with decreasing dimensions; the orifices face collection surfaces fitted with piezo-electric quartz microbalance mass sensors which weigh the particle collected by each stage during collection.
The specifications for the piezo-balance impactor are given in Table C.8.

Table C.8 — Specifications for piezo-balance impactor

Item Specification
Sensitivity/resolution 5 μm to 50 μm particles collected at low pressures
Linearity Significant quantity of over-and under-size deposition
Stability Cutoff size depends on the sample flow rate
Calibration interval 12 months maximum
Minimum collection sensitivity 10 μg/m3 for particles with specific gravity 2

C.4 Airflow test

C.4.1 Air velocity meter

C.4.1.1 Thermal anemometer, measures air velocity by sensing the change in heat transfer from a small, electrically heated sensor exposed to the airflow.
The specifications for the thermal anemometer are given in Table C.9.


Table C.9 — Specifications for thermal anemometer

Item Specification
Measuring limits/range 0,1 m/s to 1,0 m/s typically in the installation, 0,5 m/s to 20 m/s in duct
Sensitivity/resolution 0,05 m/s (or minimum 1 % for full scale)a
Uncertainty of measurement ±(5 % of reading +0,1 m/s)a
Response time

Kết quả (Việt) 1:

C.3 Macroparticle count C.3.1 Microscopic measurement of particles collected on filter paper, see ASTM F312[4]C.3.2 Cascade impactor, particle collection system where sample is passed at a constant flow rate through a series of orifices of decreasing dimensions; the orifices face the collection surfaces. As fluid velocity increases through each orifice-collector stage, smaller particles are collected for weighing or counting after collection. The specifications for the cascade impactor are given in Table C.5. Table C.5 — Specifications for cascade impactorItem SpecificationMeasuring limits/range Sampling flow rate as specifiedSensitivity/resolution Sub-micrometer particles can be collected at low pressure Accuracy Stage “cut-point” accuracy is ≥90 % Linearity Significant quantity of over-and under-size depositionStability 50 %. Cutoff size depends on the sample flow rateResponse time Minutes to days, depending on sample measurement methodCalibration interval 12 months maximumC.3.3 Discrete-macroparticle counter, instrument capable of counting and sizing (when required) single airborne macroparticles. The specifications for the discret-macroparticle counter are given in Table C.6. Table C.6 — Specifications for discrete-macroparticle counterItem SpecificationMeasuring limits/range Particle concentration to 1,0 ×106/m3Sensitivity/resolution 5 μm to 80 μm with 20 % resolutionUncertainty of measurement Sizing error ±5 % of calibration setting Linearity Can vary with particle composition or shapeCalibration interval 12 months maximumCounting efficiency (50 ±20) % at minimum size threshold and (100 ±10) % for particles greater than or equal to 1,5 times the minimum threshold size.C.3.4 Time-of-flight particle sizing apparatus, discrete-particle counting and sizing apparatus that defines the aerodynamic diameter of particles by measuring the time for a particle to accommodate to a change in air velocity. This is usually done by measuring the particle transit time optically after a fluid stream velocity change. The specifications for the time-of-flight particle sizing apparatus are given in Table C.7. Table C.7 — Specifications for time-of-flight particle sizing apparatusItem SpecificationMeasuring limits/range Particle concentration to 1,0 ×107/m3Sensitivity/resolution 0,5 μm to 20 μm with 20 % resolutionUncertainty of measurement ±5 % of calibration size setting Calibration interval 12 months maximumCounting efficiency (50 ±20) % at minimum size threshold and (100 ±10) % for particles greater than or equal to 1,5 times the minimum threshold sizeC.3.5 Piezo-balance impactor, particle collection system where the sample is passed at a constant rate through a series of orifices with decreasing dimensions; the orifices face collection surfaces fitted with piezo-electric quartz microbalance mass sensors which weigh the particle collected by each stage during collection. The specifications for the piezo-balance impactor are given in Table C.8.

Table C.8 — Specifications for piezo-balance impactor

Item Specification
Sensitivity/resolution 5 μm to 50 μm particles collected at low pressures
Linearity Significant quantity of over-and under-size deposition
Stability Cutoff size depends on the sample flow rate
Calibration interval 12 months maximum
Minimum collection sensitivity 10 μg/m3 for particles with specific gravity 2

C.4 Airflow test

C.4.1 Air velocity meter

C.4.1.1 Thermal anemometer, measures air velocity by sensing the change in heat transfer from a small, electrically heated sensor exposed to the airflow.
The specifications for the thermal anemometer are given in Table C.9.


Table C.9 — Specifications for thermal anemometer

Item Specification
Measuring limits/range 0,1 m/s to 1,0 m/s typically in the installation, 0,5 m/s to 20 m/s in duct
Sensitivity/resolution 0,05 m/s (or minimum 1 % for full scale)a
Uncertainty of measurement ±(5 % of reading +0,1 m/s)a
Response time <1 s at 90 % of full scale
Calibration interval 12 months maximum
a For the sensitivity and uncertainty of measurement, refer to ISO 7726. The apparatus needs the corrections to air temperature difference and changes of atmospheric pressure.


C.4.1.2 Ultrasonic anemometer, 3-dimensional or equivalent, measures air velocity by sensing the shift of sound frequency (or acoustic velocity) between separated points in the measured airflow.
The specifications for the ultrasonic anemometer are given in Table C.10.

Table C.10 — Specifications for ultrasonic anemometer, 3-dimensional or equivalent

Item Specification
Measuring limits/range 0 m/s to 1 m/s in the installation
Sensitivity/resolution 0,01 m/s
Uncertainty of measurement ±5 % of reading
Response time <1 s
Calibration interval 12 months maximum

C.4.1.3 Vane-type anemometer, measures air velocity by counting the revolution rate of the anemometer vanes the airflow.
The specifications for the vane-type anemometer are given in Table C.11.

Table C.11 — Specifications for vane-type anemometer

Item Specification
Measuring limits/range 0,2 m/s to 10 m/s
Sensitivity/resolution 0,1 m/s
Uncertainty of measurement ±0,2 m/s or ±5 % of reading, whichever is greater
Response time <10 s at 90 % of full scale
Calibration interval 12 months maximum

C.4.1.4 Pitot-static tubes and manometer (digital), measure air velocity from the difference of total and static pressures at a position in the airflow, using electrical digital manometers.
The specifications for the Pitot-static tube and manometer are given in Table C.12.

Table C.12 — Specifications for Pitot-static tube and manometer

Item Specification
Measuring limits/range >1,5 m/s
Sensitivity/resolution 0,5 m/s
Uncertainty of measurement ±5 % of reading
Response time <10 s at 90 % of full scale
Calibration interval 12 months maximum

C.4.2 Airflow meter

C.4.2.1 Flowhood with flowmeter, measures airflow rate from an area over which there can be variations in airflow, providing an integrated air volume from that area. The total airflow is collected and concentrated so that the velocity at the measurement point represents the cross-sectional average velocity
from the total area.
The specifications for the flowhood with flowmeter are given in Table C.13.

Table C.13 — Specifications for flowhood with flowmeter

Item Specification
Measuring limits/range Flow rate of 503m/hr to at least 1 700 m3/hra
Uncertainty of measurement ±5 % of reading
Response time <10 s at 90 %
Calibration interval 12 months maximum
a Typical range for size 600 ×600 mm hood. Measuring limits and the resolution depend on the size of hood used.


C.4.2.2 Orifice meter, refer to ISO 5167-2:2003[20].

C.4.2.3 Venturi meter, refer to ISO 5167-4:2003[22]
.
C.5 Air pressure difference test

C.5.1 Electronic micromanometer, used to display or output the value of the air pressure difference between a space and its surroundings by detecting the change of electrostatic capacitance or electronic resistance due to the displacement of a diaphragm.
The specifications for the electronic micromanometer are given in Table C.14.

Table C.14 — Specifications for electronic micromanometer

Item Specification
Measuring limits/range 0 kPa to 0,3 kPa, or 0 kPa to 1,5 kPa
Sensitivity 1 Pa for 0 kPa to 0,3 kPa
Uncertainty of measurement ±3 % for 0 kPa to 0,3 kPa
Scale amplitude power 2 (at minimum) to 10 at 0 kPa to 0,3 kPa

C.5.3 Mechanical differential pressure gauge, used to measure the air pressure difference between two areas by detecting the movement distance of a needle connected with a mechanical gear or magnetic linkage to the displacement of a diaphragm.
The specifications for the mechanical differential pressure gauge are given in Table C.16.

Table C.16 — Specifications for mechanical differential pressure gauge

Item Specification
Measuring limits/range 0 Pa to 50 Pa for a small range; 0 kPa to 50 kPa for a large range
Sensitivity/resolution 0,5 Pa for 0 Pa to 50 Pa range
Uncertainty of measurement ±5 % full-scale for 0 Pa to 50 Pa
±2,5 % full-scale for 0 kPa to 50 kPa

C.6 Installed filter system leakage test

C.6.1 Aerosol photometers

C.6.1.1 Linear aerosol photometer, used to measure the mass concentration of aerosols in micrograms per litre (μg/l). The photometer uses a forward scattered-light optical chamber to make this measurement. This apparatus may be used to measure filter leak penetration directly.
The specifications for the linear aerosol photometer are given in Table C.17.

Table C.17 — Specifications for linear aerosol photometer

Item Specification
Measuring limits/range 0,001 μg/l to 100 μg/l −5 full linear decades
Sensitivity/resolution 0,001 μg/l
Uncertainty of measurement ±5 %
Linearity ±0,5 %
Stability ±0,002 μg/l per minute
Response time From 0 % to 90 %, ≤30 s; from 100 μg/l to 10 g/l, ≤60 s
Calibration interval 12 months or 400 operating hours, whichever is sooner
Sample probe tube length Maximum length is 4 m
Particle size 0,1 μm to 0,6 μm over measuring range
Sample flow Nominal flow rate ±15 %
Sample probe See B.6.2.4
C.6.1.2 Logarithmic aerosol photometer, used to measure the mass concentration of aerosols in micrograms per litre (μg/l). The photometer uses a forward scattered optical chamber to make this measurement. Filter leakage penetration cannot be measured directly on this apparatus.
The specifications for the logarithmic aerosol photometer are given in Table C.18.

Table C.18 — Specifications for logarithmic aerosol photometer

Item Specification
Measuring limits/range 0,001 μg/l to 100 μg/l −on one range
Sensitivity/resolution 0,001 μg/l
Uncertainty of measurement ±5 %
Stability ±0,002 μg/l per minute
Response time From 0 % to 90 %, ≤60 s; from 100 μg/l to 10 g/l, ≤90 s
Calibration interval 12 months or 400 operating hours, whichever is sooner
Sample probe tube length Maximum length is 4 m
Particle size 0,1 μm to 0,6 μm ov