Aerosol
number density and size as a function of sample temperature are critical for a
variety of applications including:
•
Characterizing
aerosol sources and sinks
•
Monitoring
aerosol evolution during transport
•
As input
to heterogeneous chemical models
•
Investigating
new particle formation and growth
•
Validating
satellite retrievals and model predictions
•
Establishing
combustion system emission factors
LARGE
deploys the following instruments to determine key aerosol microphysical
properties.
Number
Density
•
Ultrafine
Condensation Particle Counters (TSI3025a, TSI3776)
o Butanol-based CNCs
w/50% size cut ~3 nm
o 5% precision, < 1
second response
o Suitable for ground and
airborne applications; can be mated to SMPS
o Dynamic range from 1 to
1e5/cm-3
o Deployed on NASA
aircraft in dozens of studies since 1994
o http://www.tsi.com/Ultrafine-Condensation-Particle-Counter-3776/
•
Condensation
Particle Counters (TSI3010, TSI3760, TSI3772)
o Butanol-based w/50% cut
size ~10 nm, variable with condenser temp
o 5% precision, ~1 sec
response
o Dynamic range from 1 to
3e4 cm-3
o Used in conjunction
with thermal denuders to determine nonvolatile CN
o Suitable for ground and
airborne applications; 3010 and 3772 mate to SMPS
o Deployed on NASA and
NOAA aircraft on multiple missions
o http://www.tsi.com/SiteSearch.aspx?searchText=3772
•
High
concentration condensation particle counters (TSI3022, TSI3775)
o Butanol-based with cut
size ~5 nm
o Single particle and
photometric counting modes
o 10% precision, ~4
second response times
o Dynamic range from 1 to
1e7 cm-3
o Used in ground-based
applications only because of pressure sensitivity
o Used extensively in
combustion characterization studies
o http://www.tsi.com/SiteSearch.aspx?searchText=3775
•
Mixing
CNC (mCPC, Brechtel Manufacturing)
o Butanol-based w/7 nm
cut size
o <0.2 response time,
can be used with scanning electrical mobility spectrometer
o Dynamic range <1 to
1e5 cm-3
o Suitable for ground and
airborne applications
o Fast response enables
eddy-correlation flux measurements
o http://www.brechtel.com/products-item/mixing-condensation-particle-counter/
•
Water-based
Condensation Nuclei Counter (wCNC, TSI model UHSAS (Ultra-High Sensitivity
Aerosol Spectrometer)
o Water vapor
condensation w/5 nm cut size and 0.3 sec response time
o Sensitive to aerosol
composition, activates soluble aerosols more efficiently
o Condenser temperature
can be changed to investigate particle solubility
o http://www.tsi.com/General-Purpose-Water-based-Condensation-Particle-Counter-3787/
•
Cloud
Condensation Nuclei Counter (CCN, DMT model CCN-100)
o Continuous flow
stream-wise thermal gradient instrument
o Typically operated in
scanning flow mode to measure saturation spectrum in <60 secs
o Data interpretation
generally conducted in collaboration with Nenes group at GIT
o Flow on NASA Aircraft
since 2007, most recently during SEAC4RS and DISCOVER-AQ
o http://www.dropletmeasurement.com/products/airborne/CCN
Size
Distributions
•
Scanning
Mobility Particle Sizer (SMPS, TSI3081n/l, TSI3936)
o Units include long or
nano differential mobility analyzers coupled to standard or ultrafine TSI CPC
o Size range long DMA: 10
to 1000 nm
o Size range nano DMA:
2.5 to 200 nm
o Scanning time 30 to 60
seconds
o 64 size channels
typical
o Suitable for airborne
use; sizes corrected for changes in mobility with pressure
o http://www.tsi.com/Scanning-Mobility-Particle-Sizer-Spectrometer-3936/
•
Scanning
Electrical Mobility Spectrometer (SEMS, Brechtel Manufacturing)
o Unit includes long DMA
column coupled to BMI mCPC
o Size range 10 to 2000
nm
o Scanning time 10
seconds or greater
o 64 size channels
typical
o Suitable for airborne
use; sizes corrected for changes in mobility with pressure
o Extremely useful as
mono-disperse calibration aerosol generator
o http://www.brechtel.com/products-item/scanning-electrical-mobility-spectrometer/
•
Electrical
Exhaust Particle Sizer (EEPS or FMPS, TSI)
o Electrometer-based mobility
spectrometer
o Size range 5.6 to 560
nm, 0.1 sec response
o 16-channels per decade
o Dynamic range 1e3 to
1e8/cm3
o Suitable for ambient
pressure operations only
o Used extensively for
establishing combustion emission factors
o http://www.brechtel.com/products-item/scanning-electrical-mobility-spectrometer/
•
Ultra-High
Sensitivity Aerosol Spectrometer (UHSAS, DMT)
o Laser-based, optical
particle counter
o High intensity 791 nm
laser
o 99 channels over 55 to
1,000 nm range
o Suitable for ground and
airborne applications
o Flown on NASA aircraft
since 2006 (NAMMA)
o http://www.dropletmeasurement.com/products/ground-based/UHSAS
•
Laser
Aerosol Spectrometer (LAS, TSI model 3340)
o Laser-based optical
particle counter
o 100 channels over 90 to
7,500 nm diameter range
o Suitable for ground and
airborne applications
o Flown on P-3B and DC-8
during DISCOVER-AQ and SEAC4RS
o http://www.tsi.com/Laser-Aerosol-Spectrometer-3340/
•
Optical
Particle Sizer (OPS, TSI model 3330)
o Laser-based optical
particle counter
o 16 channels over the
300 to 10,000 nm diameter range
o Used in ground tests
and long-term aerosol monitoring
o Deployed in LARGE
mobile lab during DISCOVER-AQ
o http://www.tsi.com/Optical-Particle-Sizer-3330/
•
Forward-Scattering
Spectrometer Probes (FSSP-300, FSSP-100; PMS/DMT)
o Open sample cavity,
wing-mounted optical particle counters
o Derive size of
spherical particles from forward scattering light intensity
o 30 size channels over
the 0.3 to 20 m (FSSP-300) or 2 to 47 m size range (FSSP-100)
o Flown on NASA aircraft
since 1970s to measure aerosol/cloud-droplet concentrations
o https://www.eol.ucar.edu/instruments/forward-scattering-spectrometer-probe-model-100
•
Aerodynamic
Particle Sizer (APS, TSI model 3321)
o Measures particle time
of flight to determine spherical-equivalent aerodynamic size
o 52 size channels over
the 0.5 to 20 mm diameter range
o Also provides 16
channels of optical sizing over the 0.37 to 20 mm diameter range
o Suitable for ground and
airborne applications; flown on NASA aircraft since 2001
o http://www.tsi.com/uploadedFiles/_Site_Root/Products/Literature/Spec_Sheets/3321.pdf
