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ACSM UpdatePhil Croteau, Wen Xu, Mike Cubison, John Jayne
9/23/2015 AMS Users Meeting 2015 1
Q-ACSM
ToF-ACSM
Q-ACSM and ToF-ACSM Systems
15-30 min data typical 10 min data typical
9/23/2015 AMS Users Meeting 2015 2
ToF-ACSM Sensitivity is ~5x Q-ACSM in same time
Particle Inlet (1 atm)
Thermal
Vaporization
&
Electron
Impact
Ionization
Aerodynamic Lens
40-1000 nm
Particle Beam
Generation
Particle
Composition
Quadrupole Aerosol Chemical Speciation Monitor
Laptop
Computer
RG
A
Pumps (x3)
No Sizing
Commercial grade
Mass SpectrometerPfeiffer Prisma
Slow scan rates, 0.2 sec/amu
9/23/2015 AMS Users Meeting 2015 3
ETOF
Mass Spec
Particle Inlet (1 atm)
Thermal
Vaporization
&
Electron
Impact
Ionization
Aerodynamic Lens
40-1000 nm
Particle Beam
Generation
Particle
Composition
ADQ114
4-Stage Split-Flow
No Sizing
Time-of-Flight Aerosol Chemical Speciation Monitor
9/23/2015 AMS Users Meeting 2015 4
RG
A
Sample
modeFilterFilter
mode
In ACSM, the difference airbeam signal is zero.
3-way Valve
Difference mass spectrum measured by automated valve switching
9/23/2015 AMS Users Meeting 2015 5
ACSM Around the World
Q-ACSM – 81 Systems
TOF-ACSM – 12 Systems
9/23/2015 AMS Users Meeting 2015 6
Requirements for PM2.5 ACSM
9/23/2015 AMS Users Meeting 2015 7
Issue Solution
Deliver particles to the lens Redesigned inlet system
Deliver particles to the vaporizer PM2.5 Lens
Detect particle mass Capture Vaporizer
ACSM Inlet for PM2.5
• Switch to straight path for filter valve• Eliminate bends in 1/8” tube• Minimize length of 1/8” Tube
Loss in 1/8” Tube
9/23/2015 AMS Users Meeting 2015 8
Standard Lens
9/23/2015 AMS Users Meeting 2015 9
PM2.5 comparison with standard lens
9/23/2015 AMS Users Meeting 2015 10
High pressure lens/PM2.5 lens/Standard lens comparison
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Size-dependence of collection efficiency
9/23/2015 AMS Users Meeting 2015 12
Testing On-going in Nanjing, China
9/23/2015 AMS Users Meeting 2015 13
Coming soon…
• Q-ACSM to TOF-ACSM Upgrade• Q-ACSM Vacuum System with CTOF Mass spectrometer
• Currently putting together test/development system at ARI• Electronics and Software work in process
9/23/2015 AMS Users Meeting 2015 14
Thanks!
9/23/2015 AMS Users Meeting 2015 15
