View
0
Download
0
Category
Preview:
Citation preview
Welcome!欢迎欢迎欢迎欢迎!歓迎歓迎歓迎歓迎 !환영환영환영환영!Добро пожаловать!ःवागतःवागतःवागतःवागत
© 2007, TSI Incorporated© 2009, TSI Incorporated
Scanning Mobility Particle Sizing (SMPS) Key Factors for Accuracy
Добро пожаловать!ःवागतःवागतःवागतःवागत!
Note: you need to join the webinar in two ways: ov er the phone (audio) and on the internet (visual). Ready-Access phone numbers:https://g8.cfer.com/g8.jsp?an=8005048071&ac=4902732 &login=truelink and information included with e-mail login inf ormation
This webinar will begin at:Greenwich Mean Time (GMT) Thursday, 1:00amBeijing, China 8:00am Tokyo, Japan 9:00amUS CST 7:00pm (Wednesday Evening)
Kathy EricksonProduct Specialist
Particle InstrumentsApril 20, 2011
Welcome!Willkommen!Bienvenue!Benvenuto!Recepción !
© 2007, TSI Incorporated© 2009, TSI Incorporated
Recepción !Καλώς Ήρθατε!Добро пожаловать!
Note: you need to join the webinar in two ways: ov er the phone (audio) and on the internet (visual). Ready-Access phone numbers:https://g8.cfer.com/g8.jsp?an=8005048071&ac=4902732 &login=truelink and information included with e-mail login inf ormation
This webinar will begin at:Greenwich Mean Time (GMT) Thursday, 2:00pmUK, London 2:00mGermany, Berlin 3:00pmIndia 6:30pmUS CST 8:00am
Scanning Mobility Particle Sizing (SMPS) Key Factors for Accuracy
Kathy EricksonProduct Specialist
Particle InstrumentsApril 20, 2011
Welcome!欢迎欢迎欢迎欢迎!Willkommen!歓迎歓迎歓迎歓迎 !Bienvenue !ःवागतःवागतःवागतःवागत
© 2007, TSI Incorporated© 2009, TSI Incorporated
Bienvenue !ःवागतःवागतःवागतःवागत!
Note: you need to join the webinar in two ways: ov er the phone (audio) and on the internet (visual). Ready-Access phone numbers:https://g8.cfer.com/g8.jsp?an=8005048071&ac=4902732 &login=truelink and information included with e-mail login inf ormation
This webinar will begin at:Greenwich Mean Time (GMT) Thursday, 5:00pmUS PST 9:00amUS CST 11:00amUS EST 12:00pm (just after noon)Germany, Berlin 6:00pm
Scanning Mobility Particle Sizing (SMPS) Key Factors for Accuracy
Kathy EricksonProduct Specialist
Particle InstrumentsApril 20, 2011
Interactive Webinar Format
1. Connection Information: You need to join the webinar in two ways– Audio: via telephone - phone numbers and link information
included with e-mail login information– Visual: via internet - link information included login information
2. Sound quality: For large groups, the sounds quality is much better if the
© 2007, TSI Incorporated© 2009, TSI Incorporated
2. Sound quality: For large groups, the sounds quality is much better if the conference is kept on ‘mute’.
3. Multi-media - Interactive chat: Please send questions via chat during and after the presentation.
4. Follow-up: e-mail including Adobe pdf file of presentation will be sent to registered attendees.
Electrical Mobility Sizing: Outline
– Introduction & Theory
– Key Factors for Accuracy
1. DMA voltage, flows & design2. Charge Distribution3. Efficiency curve of the CPC4. DMA transfer function
© 2007, TSI Incorporated© 2009, TSI Incorporated
4. DMA transfer function5. Scan time6. Parameters of working gas7. Diffusion losses8. Aggregate correction
– ISO 15900
– ES + SMPS
– Closing Comments
Applications for Nanoparticle SizingParticle Size: Critical Metric
Nanomaterial R&D
Inhalation Toxicology Indoor Air
Quality
© 2007, TSI Incorporated© 2009, TSI Incorporated
Atmospheric Research
Manufacturing Process Control
Filter Efficiency Testing
Emission Characterization
Engine/Fuel Development
Milestones in Electrical Mobility Particle Sizing
~1900 Electrostatic classification of atmospheric aerosols1921 Erickson first Differential Mobility Analyzer (DMA)1957 Hewitt co-axial cylindrical ‘DMA’ with unipolar charging1966 Whitby & Clark ‘Whitby Aerosol Analyzer’ (TSI 1967 – first commercial system)1983 TSI ‘DMPS’ voltage stepping system 1990 Scanning concept devised by Wang & Flagan
© 2007, TSI Incorporated© 2009, TSI Incorporated
1991 Used by NIST to size 60nm (Mulholland et al 1991) 1993 First commercial scanning sizing system
Scanning Mobility Particle Sizer Spectrometer (SMPS)2005 Duke Scientific (Vasilou) evaluated scanning SMPS to size 20 to 100nm PSL
“In all cases, the SMPS mean diameter fell within the uncertainty of the reference standard [TEM].Note: surface techniques designed to image nanoparticles—not designed for sizing accuracy.
2006 Used by NIST to size 60nm & 100nm SRM (Mulholland et al 2006) 2009 ISO Standard 15900:2009 ‘Determination of particle size distribution –
Differential electrical mobility analysis for aerosol particles’2010 NIST Test Protocol ‘Analysis of Gold Nanoparticles by Electrospray Differential
Mobility Analysis (ES-DMA)’ [nanoparticle liquid colloids (sol)]
Reasons for Increased Interest in Electrical Mobility-based Sizing
– Discreet method: individual particles are counted and sized
– Large sample size
– No assumptions regarding size distribution
– Independent of optical properties of material (& liquid)
– 1st principle technique: no size calibration necessary
© 2007, TSI Incorporated© 2009, TSI Incorporated
– 1st principle technique: no size calibration necessary
– High resolution: ~±10% of particle size (or better at higher flow ratios)
“it affords an opportunity to monitor the quality of product particles in real time with size resolution that is unattainable in most other particle characterization technologies” (Flagan 2008)
– Low uncertainty: ±3.5% (Mullholand et al 1991)
– Real-time: 16-300s
– Easy to use; does not require a trained technician
Colloids Suitable for Electrical Mobility Particle Sizing
Dispersed Phase
Gas Liquid Solid
Colloids - a substance microscopically dispersed evenly throughout another substance
© 2007, TSI Incorporated© 2009, TSI Incorporated
Gas NoneAll gases are miscible
Liquid aerosol Solid aerosol
Liquid Foam Emulsion Sol
Solid Solid Foam Gel Solid sol
substance
Con
tinuo
us M
ediu
m
Electrical Mobility Analysis
Where:np = number of charges per particlee = elementary unit of chargeE = electric field strengthµ = viscosity of gasD = particle diameter
F n eEelectric p=�
FD v
Cviscousdragp
=3πµ
�
Zp ≡ electrical mobility; ability of a charged particle to traverse an electric field
© 2007, TSI Incorporated© 2009, TSI Incorporated
Dp = particle diameterC = Cunningham slip correctionv = Velocity
Cviscousdrag �
F Felectric viscous= drag�
ZvE
n eC
Dpp
p
= =3πµ� Electrical mobility: inversely
proportional to particle size
Second order function of particle size
Assumptions� Stoke’s Regime (Re<1)� Drag based on rigid sphere
Differential Mobility Analyzer (DMA)
– Classical Knutson & Whitby cylindrical DMA design (1975)
– Applied voltage
© 2007, TSI Incorporated© 2009, TSI Incorporated
determines electric field
– Laminar flow
– Particle free sheath air
– 4 balanced flows
– Monodisperse aerosol exiting DMA
Mobility Particle Sizing
Aerosol Conditioner
Differential Mobility Analyzer
Classifier
ParticleCounter
ZvE
n eC
Dpp
p
= =3πµ
© 2007, TSI Incorporated© 2009, TSI Incorporated
Control hardware & software
Counts size selected
particlesto build
distribution
Selects particles according to
electrical mobility→ particle size
Produces a known charge
distribution
Laminar Flow CPCs
© 2007, TSI Incorporated© 2009, TSI Incorporated
– Fast– Precise temperature control– Low particle losses
S = Supersaturation RatioPv = Vapor PressurePsaturation(T) = Saturation Vapor Pressure
Dkelvin = Kelvin DiameterdS = Surface Tension of Working FluidM = Molecular Weight of Working FluidrL = Density of Working FluidR = Gas ConstantT = TemperatureS = Supersaturation Ratio
DM
RT SkelvinS
L
= 4δρ log
SP
P Tv
saturation
≡( )
Assumption: particle material is readily wetted by but insoluble in the condensing vapor
Scanning Mobility Particle SizerSMPS
Polydisperse Aerosol
Scanning Voltage DMA– 1990 Wang & Flagan– If voltage is exponentially ramped, all particles follow the same trajectory in the DMA– The resolution (transfer function of the DMA) is identical to that of stepping systems– 16 to 300s (or below?)
© 2007, TSI Incorporated© 2009, TSI Incorporated
DMA
SelectsSingleSize
Counter
Monodisperse Aerosol
Voltage/Diameter
Concentration
Size Distribution
SMPS: Key Factors for Accuracy
1. DMA voltage, flows & design2. Charge distribution
6. Scan time7. Parameters of working gas
True: 1st Principle Device: No calibration required
Also True: Data Inversion - Electrical Mobility to Particle Size
© 2007, TSI Incorporated© 2009, TSI Incorporated
2. Charge distribution3. Efficiency curve of the CPC4. DMA transfer function
7. Parameters of working gas8. Diffusion losses9. Aggregate correction
DMA Voltage & Flowrates
)r
rln()]qq(2/1q[
Z 1
2mpt +−
=
ZvE
n eC
Dpp
p
= =3πµ
© 2007, TSI Incorporated© 2009, TSI Incorporated
VL2Z 1
p π=
Where:qt = total flowrate (sheath + poly)qm = monodisperse flowrateqp = polydisperse flowrater2 = outer electrode radiusr1 = inner electrode radius V = voltage on center electrodeL = length between sample exit and aerosol inlet
‘Nano’ Differential Mobility Analyzer
– Designed in collaboration with the University of Duisburg and the University of MN
– Aim to improve nanometer size resolution• Shortening effective length• Eliminate flow and electric field non-uniformities• Minimize diffusion broadening
© 2007, TSI Incorporated© 2009, TSI Incorporated
• Minimize diffusion broadening• Increase transmission efficiency
1. Reduce particle losses due to diffusion 2. Reduce losses due to electrostatic forces
– DMA design governs• Size range • Ideal resolution (increased resolution <10nm
results in decreased size range)• Electric field & flow uniformities (manufacturing
non-conformities can also affect this).
DMA Voltage & Flowrates
Voltage1) Reliable high voltage supply &
electronics2) Calibrated using NIST Traceable
meters
Flow1) Laminar flow element
© 2007, TSI Incorporated© 2009, TSI Incorporated
1) Laminar flow element2) Re-circulating flow scheme to
minimizes flow disturbances (decreased resolution)
3) NIST Traceable flow meters4) Volumetric flow rate: atmospheric
temperature & pressure adjustment. 5) Periodically check flow accuracy with
independent volumetric flow meter.
Charges Per Particle
Must know number of charges per particle
Particle VelocityElectric Field Strength 3πµDp
neC===Zp
VE
Equilibrium Charge Distribution
Need to Generate Bi -polar Ions
© 2007, TSI Incorporated© 2009, TSI Incorporated
Need to Generate Bi -polar Ions
Note: Poor charging leads predominately to concentration inaccuracies. However, since charging is size dependent it leads to sizing inaccuracies as well.
Two Neutralizers
Aerosol Out
+++
+
+
++
+ ++ --- --
--
--
-Aerosol In
Kr-85 gas
TraditionalKr-85 gas
Advanced Aerosol NeutralizerSoft X-ray
– Nonradioactive– Comparable SMPS
© 2007, TSI Incorporated© 2009, TSI Incorporated
sealed stainless-steel tube
Kr-85 facts– Kr-85 inert gas sealed in air-tight stainless steel – Never absorbed by the body– In US classified as a “non-biological health hazard”– In US no handling limitations for amount used in SMPS– 10.4 year half life– Beta-emitter
sizing– No transportation
restrictions– Does not decay
over time
Poor Charging: Soot Aerosol
Generated aerosol is very highly charged
© 2007, TSI Incorporated© 2009, TSI Incorporated
High soot aerosol concentration and 1 neutralizer TSI model 3077: SMPS measurement shows that charge equilibrium was not reached
Diluted soot aerosol and neutralizers TSI models 3077 and 3012 in series:Charge equilibrium was reached
If the aerosol is highly charged & poorly neutralize d (left hand side) large errors in size distribution and concentration.
Multiple ChargesFuch’s Equilibrium Charge Distribution
Dp (nm) -2 -1 0 +1 +2
10 0 5.03 90.96 4.02 0
Percent of particles carrying np elementary charge units
© 2007, TSI Incorporated© 2009, TSI Incorporated
10 0 5.03 90.96 4.02 020 0.02 11.14 80.29 8.54 0.0150 1.13 22.94 58.10 17.20 0.6370 2.80 26.02 49.99 19.53 1.57100 5.67 27.42 42.36 20.75 3.24130 8.21 27.30 37.32 20.85 4.77200 12.18 25.54 29.96 19.65 7.21300 14.56 22.71 24.16 17.51 8.65500 15.09 18.60 18.28 14.33 8.95700 14.29 15.94 15.15 12.27 8.46
1000 12.86 13.33 12.36 10.24 7.59
FromA. Wiedensohler: “An Approximation of the Bipolar Charge Distribution for Particles in the Submicron Size Range”, Journal of Aerosol Science, Vol. 19, No. 3, pp. 387-389, 1988.
Multiple Charge Correction→ Useful for larger aerosols
→ Must use impactor (physical size cut ≅ no larger multiple particles)
→ Works best if impactor cut point is just to the right of complete distribution
• Too far to the right—no effect
• Cut into size
© 2007, TSI Incorporated© 2009, TSI Incorporated
• Cut into size distribution—will see notch in distribution
→ Best to view distribution, and use if makes sense
Efficiency Curve of CPCCPC Efficiency Curve
Cou
ntin
g E
ffici
ency
%
50% cut point ~ 2.5 nm
© 2007, TSI Incorporated© 2009, TSI Incorporated
Particle Diameter (nm)
Cou
ntin
g E
ffici
ency
%
50% cut point ~ 2.5 nm
CPC Efficiency curves affected by:1) Instrument to instrument
variation2) Working fluid3) Carrier gas (Niida et al 1988)
Sizing Accuracy:1) Most applications, small CPC efficiency curve
differences have very little effect on accuracy.2) Nanoparticle applications can be sensitive to
efficiency curves: large numbers of particles close to the lower detection limit.
3) Can generate custom efficiency curve to use in data inversion (Liu et al 2006).
Zp∆∆∆∆Zp = qs
qa
DMA Transfer FunctionTransfer Function ≡ probability that an entering particle with a specific electrical mobility will have the correct trajectory to exit through the exit slit with the classified aerosol. (Knutson & Whitby 1975) Ideal Transfer Function
Con
cent
ratio
n
Where:qa = aerosol flowrate
© 2007, TSI Incorporated© 2009, TSI Incorporated
Con
cent
ratio
n
Particle Diameter Dp (nm)
9nm
NDMA Transfer Function
qa = aerosol flowrateqs = sheath flowrateZp = set mobility
(Knutson & Whitby 1975)
Electrical Mobility
Effect of sheath:Sample Flow Ratio on SMPS Transfer Function
Electrospray Aerosol: No TDMA 10:1 sheath:Sample Flow rate on DMA 1 2:1 Sheath:Sample Flow rate on DMA 1
Tandom DMA Experimental Setup: Adjust flow ratio on DMA 1
+ElectroSpray
Aerosol Generator
MODEL
3480 + DMA 1 DMA 2
© 2007, TSI Incorporated© 2009, TSI Incorporated
Effect of Sheath:Sample Flow Ratio on Electrostatic Classifier
10:1 sheath:Sample Flow rate on DMA 2 5:1 sheath:Sample Flow rate on DMA 2 2:1 sheath:Sample Flow rate on DMA 2
+ElectroSpray
Aerosol Generator
MODEL
3480 + DMA 1 DMA 2
Tandom DMA Experimental Setup: Adjust flow ratio on DMA 2
© 2007, TSI Incorporated© 2009, TSI Incorporated
Diffusion Broadening
– Widens the transfer function for nanoparticles <100nm
– Reduces peak transmission efficiency
– More severe at lower voltages
© 2007, TSI Incorporated© 2009, TSI Incorporated
– More severe at lower voltages
– Significant for particles <20nm
– Stolzenberg (1998) created a model for the diffusion-broadened transfer function
– Shortening the effective length of the DMA & increasing the flowrate through the DMA:
1. reduces diffusion broadening
2. reduces the size range
Scan Time
a) 300 s b) 16 s
Electrospray Sucrose Aerosol
© 2007, TSI Incorporated© 2009, TSI Incorporated
Scan Time
a) 300 s b) 16 s c) 16 s scan range 6.98 – 12 nm
Fast Scanning - CPC features1) Laminar flow2) Fast response3) High aerosol flow rate/high concentration aerosol
Electrospray Sucrose Aerosol
© 2007, TSI Incorporated© 2009, TSI Incorporated
Russell et al (1995) noted ‘scan time effect’: for very short scans, tails toward larger distributions; theorized result of turbulent mixing in plumbing between DMA & CPC & internal to CPC - primarily notable on older 3071A classifier platforms & CPCs.
Cunningham Slip Coefficient
Parameters of Working GasWorking gas ≅ sheath gas in the DMA.
Note: If using a recirculating flow scheme, the sample carrier gas will eventually become the sheath gas.
Particle VelocityElectric Field Strength 3πµDp
neC===Zp
VE
µ and C both affected by working gas properties
© 2007, TSI Incorporated© 2009, TSI Incorporated
→ C = ƒ(λλλλ, Dp); λλλλ = mean free path of working gas → Empirical formula dependent on gas T & P→ In free molecular regime Kn>>1 (<10nm); C→1.7
Software Calculates µ & λλλλ• Classifier measures T&P of
air
• Software calculates gas viscosity (µ) and mean free path (λλλλ) for every sample (based on air)
Other Working Gases
– Flowmeters are calibrated with Air (must manually measure
Gas Property Air N 2 Ar CO 2 He
µ (10-4g/cm-s) 1.82 1.75 2.2 1.47 1.95
λ (10-6 cm) 6.64 6.41 6.75 4.69 18.7
© 2007, TSI Incorporated© 2009, TSI Incorporated
– Flowmeters are calibrated with Air (must manually measure and control flow)
– Noble gases have breakdown voltages much lower than air: this will effectively reduce the upper end size range (Meek & Craggs 1978)
– Bipolar charge distribution differs—can use extended Fuchs model (Wiedensohler 1991)
– CPC efficiencies differ in gases other than air (Ahn 1990)– Karg et al (1992), Schmid (2002) investigated DMA accuracy
in N2, Ar, CO2 & He and generally concluded no fundamental effect of gas type
Diffusion LossesDiffusion is a stronger than gravitational forces for particle <100nm
Circular Tube Penetration Efficiency
0.8
0.9
1.0Diffusion losses are size dependent.
© 2007, TSI Incorporated© 2009, TSI Incorporated
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.00001 0.0001 0.001 0.01 0.1 1DLQ
Pen
etra
tion
Gormley and Kennedy (1949) derived an equation for circular tube penetration efficiency.
D = Diffusion coefficient; D = ƒ(T, Gas type, d p))L = Length of tubeQ = Volumetric flow rate
Diffusion LossesSMPS Diffusion loss:
1) Sampling scheme
2) System losses through• Controller platform• DMA• CPC
Diffusion losses ���� with:
1) Increasing tubing length
2) Decreasing particle diameter
3) Increasing temperature
© 2007, TSI Incorporated© 2009, TSI Incorporated
• CPC• Connection tubing
– Software option for diffusion loss correction
– Uses hardware settings to estimate diffusion loss and apply correction
– Empirical and calculated contributions.
– Can apply diffusion loss correction to previously collected data
Diffusion Loss AlgorithmExample – Ambient Air
© 2007, TSI Incorporated© 2009, TSI Incorporated
Without correction With correction
Aggregates– Zp derivation assumes spherical model for drag force– Equilibrium charge distribution based on spheres– Nanoparticle aggregate correction option– Input
• estimated primary particle size• estimated agglomerate orientation (typically parallel)
© 2007, TSI Incorporated© 2009, TSI Incorporated
• estimated agglomerate orientation (typically parallel)– Can apply to previously collected data– Lall & Friedlander (2006)
Aggregate Correction - Example
dV
/dlo
g(d m
), #
/cc
50x109
100x109
150x109
200x109
250x109
), n
m2 /c
m3
10x109
12x109
14x109
16x109
18x109
Surface Area
MassSpherical assumption: redAggregate correction: greenPrimary particle diameter = 17nmParallel orientation
© 2007, TSI Incorporated© 2009, TSI IncorporatedMobility Diameter (dm), nm
10 100 1000
dN/d
logd
m,
#/cc
0
100x103
200x103
300x103
400x103
500x103
Mobility Diameter (dm), nm
10 100 10000
Mobility Diameter (dm), nm
10 100 1000
dA/d
log(
d m),
nm
0
2x109
4x109
6x109
8x109
10x10
Number
– Aggregate drag model (Chan & Dahneke 1981)
– Aggregate charge distribution (Wen et al 1984)
ISO 15900:2009
– Aimed at user; not developers– Describes differential electrical mobility
ISO 15900:2009Determination of particle size distribution — Differe ntial electrical mobility analysis for aerosol particlesDétermination de la distribution granulométrique —Analyse de mobilité électrique différentielle pour les particules d'aérosol
Table 1 – Values of Parameters Recommended for the Calculation of the Electrical Mobility From the Particle Size in Air
© 2007, TSI Incorporated© 2009, TSI Incorporated
– Describes differential electrical mobility analysis
– Raises awareness– Gives guidance on important issues
• Slip correction factor• Size dependent charge distribution• Methods for data inversion
ISO 10808:2010 Characterization of nanoparticles in inhalation exposure chambers for inhalation toxicity testing
ISO 28439:2011 Workplace atmospheres -- Characterization of ultrafine aerosols/nanoaerosols -- Determination of the size distribution and number concentration using differential electrical mobility analysing systems
Nanoparticle Colloids (Sols)ES + SMPS
Sizing Nanoparticles In LiquidsElectrospray + SMPS = ES+SMPS
– Increased interest in the last decade for high resolution liquid nanoparticle sizing
– Wide array of peer reviewed publications
© 2007, TSI Incorporated© 2009, TSI Incorporated
– Wide array of peer reviewed publications• Gold (Au) [Bottinger et al 2007, Tsai et al
2008] • Carbon Nanotubes (CNT), [Pease et al
2009]• Protein-coated Quantum Dots (QD), [Pease
et al 2010]• Copper (Cu), [Elzey et al 2010]• Silver (Ag), [Elzey et al 2010]• Iron Oxide (FexOy) ,[Hildebrandt et al 2010]
Closing CommentsScanning Mobility Particle Sizing– Rapid, high resolution size nanoparticle size distribution measurements– Discreet technique with large sample size– No assumptions regarding size distribution– Low uncertainty– Easy to use– Useful for:
1. liquid aerosols
Ovalbumin (AG501-X8)
6.38
(#/c
m3)
[e7]
© 2007, TSI Incorporated© 2009, TSI Incorporated
1. liquid aerosols2. solid aerosols3. nanoparticles suspended in liquids (sols)
3.22
3.72
4.61
8.20
Mobility Diameter (nm)
dN/d
logD
p(#
/cm
3) [e
7]
Considerations– Measures mobility � particle size is calculated– Limits to particle size range; <1µm– Proper neutralization is fundamental– Size resolution can be degraded by
1. Design defects: imperfect flow fields or electric fields
2. Low voltages: increases diffusion broadening � decreases resolution
3. Too short of scans
Thank You For
© 2007, TSI Incorporated© 2009, TSI Incorporated
Thank You For Your Attention
Any Questions?Any Questions?Kathy Erickson (kerickson@tsi.com)Kathy Erickson (kerickson@tsi.com)
Webinar ScheduleMay 5 th Using TDMAs to Measure Haze
by Tim Johnson
May 19 th Electrospray with SMPS (ES+SMPS) for Size Measureme nts of Nanoparticles Suspended in Liquids by Dr. Stan K aufman
June 23 rd Indoor Exposure to Ultrafine Particles: Sources and Measurements by Dr. Lance Wallace
July 21st Toxicological Evidence that Inhalation of Nanoscale
TSITSITSITSI PARTICLE NEWSPARTICLE NEWSPARTICLE NEWSPARTICLE NEWS
www.tsi.com/webinars
© 2007, TSI Incorporated© 2009, TSI Incorporated
July 21st Toxicological Evidence that Inhalation of NanoscaleParticulates in Urban Air Pollution is Associated w ith Cognitive Impairment by Dr. David Davis (USC)
• Size resolution <5% at 0.5 µµµµm • User adjustable size channels• Size range: 0.3 – 10 µµµµm in up to
16 channels• Wide concentration range
from 0 to 3000 particles/cm 3
• Fully compliant with ISO 21501-01/04
Optical Particle Sizer Model 3330
US +1 651-490-2811 EURO +49 241-52303-0 ASIA + 86 10 8251 6588 info@tsi.comwww.tsi.com
New WCPC’s Models 3787 & 3788
• 2.5nm detection • Single particle counting to
4x105 particles/cm3• <100 ms rise-time response
w/ 42 ms time constant (fastest CPC available)
• Convenient, eco-friendly water as working fluid Model 3788
Recommended