Comprehensive particulate matter measurement system and method for using the same
View Patent ↗A comprehensive particulate matter measurement system (CPMMS) that measures accurate mass size distribution of particulate matter (PM) in ambient air, and a method to measure the accurate mass size distribution of PM are provided. The CPMMS includes a mass-based PM sampler, a particle sizing device, and an analysis system that manipulates data sent from the mass-based PM sampler and the particle sizing device to accurately measure mass size distribution of PM. The mass-based PM sampler measures total mass concentration of PM, and the particle sizing device measures size or volume size distribution of PM. Estimated total mass concentration is obtained from the size distribution predicting an assumed density of PM, and is compared with the actual total mass concentration measured by the mass-based PM sampler. A correct density of PM can be obtained from the actual total mass concentration, and as a result, accurate mass size distribution can be obtained.
1. A method of measuring mass size distribution of particulate matter, comprising:
sampling particulate matter;
measuring an actual total mass concentration of the particulate matter using a mass-based particulate matter sampler;
measuring a non-mass-based size distribution of the particulate matter;
simulating the mass-based particulate matter sampler;
obtaining an estimated total mass concentration of the particulate matter based on the measured non-mass-based size distribution of the particulate matter and the simulated mass-based particulate matter sampler;
comparing the estimated total mass concentration with the actual total mass concentration;
obtaining a correct density of the particulate matter, and
obtaining an actual mass size distribution of the particulate matter from the correct density.
2. The method of claim 1 , comprised of the step of measuring of the non-mass-based size distribution being performed by a particle sizing device.
3. The method of claim 1 , comprised of the step of obtaining an estimated total mass concentration comprising steps:
predicting an assumed density of the particulate matter; and
obtaining an assumed mass size distribution of the particulate matter based on the non-mass-based size distribution and the assumed density.
4. The method of claim 3 , comprised of the correct density of the particulate matter being derived from a formula, ρ=ρ A C / M, where ρ is the correct density of the particulate matter, π A the assumed density sued by the particle sizing device, C the actual total mass concentration, and M the estimated total mass concentration.
5. The method of claim 3 , comprised of the step of simulating the mass-based particulate matter sampler including a step of simulating a sampling effectiveness of the mass-based particulate matter sampler, and comprised of the step of obtaining the estimated total mass concentration comprising a step of calculating the estimated total mass concentration from a formula
M
=
∑
i
p
(
i
)
c
I
(
i
)
where M is the estimated total mass concentration, p( i ) the sampling effectiveness of the mass-based particulate matter sampler in size interval i, and C I(i) the assumed mass size distribution in size interval i.
6. The method of claim 5 , comprised of the sampling effectiveness being simulated by a formula
p
(
i
)
=
1
1
+
[
D
(
i
)
/
D
50
]
n
where P (i) is the sampling effectiveness of the mass-based particulate matter sampler in size interval i, D (i) a representative aerodynamic diameter of particles in size interval i, D 50 a sampler cut point diameter, and n a parameter determining the steepness of the sampling effectiveness.
7. The method of claim 3 , comprised of the step of obtaining actual mass size distribution of particulate matter by a formula
c
(
i
)
=
c
I
(
i
)
C
M
where c (i) represents the actual mass size distribution of the particulate matter in size interval i, c I(i) the assumed mass size distribution the particulate matter in size interval i, C the actual total mass concentration of the particulate matter, and M the estimated total mass concentration of the particulate matter.
8. A comprehensive particulate matter measurement system for measuring mass size distribution of particulate matter, comprising:
a mass-based particulate matter sampler for sampling particulate matter and for measuring an actual total mass concentration of the particulate matter;
a particle sizing device for measuring a non-mass-based size distribution of the particulate matter; and
an analysis system including an analysis system readable storage medium; the analysis system being coupled to each of the mass-based particulate matter sampler and the particle sizing device; the storage medium providing instructions that cause the analysis system to perform operations to obtain a mass size distribution of the particulate matter; the operations comprising:
causing the analysis system to receive the actual total mass concentration of the particulate matter from the mass-based particulate matter sampler;
causing the analysis system to receive the non-mass-based size distribution of the particulate matter from the particle sizing device;
simulating the mass-based particulate matter sampler;
obtaining an estimated total mass concentration of the particulate matter based on the non-mass-based size distribution of the particulate matter and the simulated mass-based particulate matter sampler;
comparing the estimated total mass concentration with the actual total mass concentration;
obtaining a correct density of the particulate matter; and
obtaining an actual mass size distribution of the particulate matter from the correct density.
9. The comprehensive particulate matter measurement system of claim 8 , comprised of the step of simulating the mass-based particulate matter sampler including a step of simulating a sampling effectiveness of the mass-based particulate matter sampler, and comprised of the operation for obtaining the estimated total mass concentration including operations comprising:
predicting an assumed density of the particulate matter;
obtaining an assumed mass size distribution based on the non-mass-based size distribution and the assumed density of the particulate matter; and
calculating the estimated total mass concentration from a formula
M
=
∑
i
p
(
i
)
c
I
(
i
)
where M is the estimated total mass concentration, p (i) the sampling effectiveness of the mass-based particulate matter sampler in size interval i, and C I(i) the assumed mass distribution in size interval i.
10. The comprehensive particulate matter measurement system of claim 9 , wherein the sampling effectiveness is simulated by a formula
p
(
i
)
=
1
1
+
[
D
(
i
)
/
D
50
]
n
where p (i) is the sampling effectiveness of the mass-based particulate matter sampler in size interval i, D (i) a representative aerodynamic diameter of particles in size interval i, D 50 a sampler cut point diameter, and n a parameter determining the steepness of the sampling effectiveness.
11. The comprehensive particulate matter measurement system of claim 9 , comprised of the operation for obtaining the actual mass size distribution of the particulate matter by a formula
c
(
i
)
=
c
I
(
i
)
C
M
where c (i) represents the actual mass size distribution of the particulate matter in size interval i, c I(i) the assumed mass size distribution of the particulate matter in size interval i, C the actual total mass concentration of the particulate matter, and M the estimated total mass concentration of the particulate matter.
12. The comprehensive particulate matter measurement system of claim 9 , wherein the correct density of the particulate matter is derived from a formula, ρ=ρ A C / M, where ρ is the correct density of the particulate matter, ρ A the assumed density, C the actual total mass concentration, and M the estimated total mass concentration.
13. A machine readable storage medium providing instructions that cause the machine to perform operations to obtain a mass size distribution of particulate matter; the operations comprising:
causing the machine to receive an actual total mass concentration of the particulate matter;
causing the machine to receive a non-mass-based size distribution of the particulate matter;
simulating the mass-based particulate matter sampler;
obtaining an estimated total mass concentration of the particulate matter based on the non-mass-based size distribution of the particulate matter and the simulated mass-based particulate matter sampler;
comparing the estimated total mass concentration with the actual total mass concentration;
obtaining a correct density of the particulate matter; and
obtaining an actual mass size distribution of the particulate matter from the density.
14. The machine readable storage medium of claim 13 , comprised of the operation for causing the machine to receive an actual total mass concentration of the particulate matter including an operation for causing the machine to receive the actual total mass concentration of the particulate matter from a mass-based particulate matter sampler that is coupled to the machine.
15. The machine readable storage medium of claim 13 , comprised of the operation for causing the machine to receive a size distribution of the particulate matter including an operation for causing the machine to receive the size distribution of the particulate matter from a particle sizing device that is coupled to the machine.
16. The machine readable storage medium of claim 13 , comprised of the step of simulating the mass-based particulate matter sampler including a step of simulating a sampling effectiveness of the mass-based particulate matter sampler, and comprised of the operation for obtaining the estimated total mass concentration including operations comprising:
predicting an assumed density of the particulate matter;
obtaining an assumed mass size distribution based on the non-mass-based size distribution and the assumed density of the particulate matter; and
calculating the estimated total mass concentration from a formula
M
=
∑
i
p
(
i
)
c
I
(
i
)
where M is the estimated total mass concentration, P (i) the sampling effectiveness of the mass-based particulate matter sampler in size interval i, and C l(a) the assumed mass distribution in size interval i.
17. The machine readable storage medium of claim 16 , wherein the sampling effectiveness is simulated by a formula
p
(
i
)
=
1
1
+
[
D
(
i
)
/
D
50
]
n
where p (i) is the sampling effectiveness of the mass-based particulate matter sampler in size interval i, D (i) a representative aerodynamic diameter of particles in size interval i, D 50 a sampler cut point diameter, and n a parameter determining the steepness of the sampling effectiveness.
18. The machine readable storage medium of claim 16 , comprised of the operation for obtaining actual mass size distribution of particulate matter by a formula
c
(
i
)
=
c
I
(
i
)
C
M
where c (i) represents the actual mass size distribution of the particulate matter in size interval i, c I(i) the assumed mass size distribution of the particulate mailer in size interval i, C the actual total mass concentration of the particulate matter, and M the estimated total mass concentration of the particulate matter.
19. The machine readable storage medium of claim 16 , wherein the correct density of the particulate matter is derived from a formula, ρ=ρ A C / M, where ρ is the correct density of the particulate matter, ρ A the assumed density, C the actual total mass concentration, and M the estimated total mass concentration.