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2/21/2016
1
Real Time Dust Monitoring
Strategies and Tools
Scott Norman, CIH CSP
Product Specialist
TSI Incorporated
Shoreview MN
© TSI Incorporated
March 22, 2016 Indiana H&S Conference
Real time measurement
instruments
+ Speedometer
+ Altimeter
+ Thermometer
+ Scale
+ Sound pressure level meter
+ Data logging noise dosimeter
+ RF Survey meter
+ PID / FID
+ Geiger counter
+ Confined Space 4-gas monitor
March 22, 2016
“Do you know how fast you
were going?”
http://www.flickr.com/photos/oregondot/3698915292/Oregon Department of Transportation
2©TSI Incorporated
2/21/2016
2
Goal – to introduce some strategies and
associated tools used for monitoring dust in real-time.
What are aerosols
How do we measure aerosols
Types of real time aerosol measurement
instruments
How light scattering photometric instruments work
Strengths and limitations of these instruments
Application examples
Q&A
March 22, 2016 3©TSI Incorporated
+ Dust
Aerosol
March 22, 2016 4©TSI Incorporated
2/21/2016
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+ Dust
+ Fume
Aerosol
March 22, 2016 5©TSI Incorporated
+ Dust
+ Fume
+ Mist
Aerosol
March 22, 2016 6©TSI Incorporated
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+ Dust
+ Fume
+ Mist
+ Smoke
Aerosol
March 22, 2016 7©TSI Incorporated
Aerosol Size Matters
March 22, 2016 8©TSI Incorporated
2/21/2016
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Respiratory Tract
Based on International Commission of Radiological Protection (1994) and U.S. Environmental Protection Agency (1996a).Air Quality Criteria for Particulate matter, 2004, p 6-5.
+ Extrathoracic region
+ Tracheobronchial region
+ Alveolar region
>PM 10
PM 10-PM 4
<PM 4
March 22, 2016© TSI Incorporated 9
“How Big”
March 22, 2016
Click to open “How Big”
10©TSI Incorporated
2/21/2016
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+ Pump
+ Sampling Cassette
+ Media
+ Cyclone
+ Tubing
Pump
Measurement of Aerosols
Traditional IH Air Sampling
Equipment
March 22, 2016 11©TSI Incorporated
+ Calibrate pump
+ Place on worker, turn on pump
+ Record start time
+ Turn off pump, cap cassette,
document time
+ Post-calibrate pump
+ Calculate run time
+ Document run times, calibrations,
sample ID
+ Prepare chain of custody form
+ Package for shipping
+ Complete shipping paper work
Pump
Measurement of Aerosols
Traditional IH Air Sampling
process steps
March 22, 2016 12©TSI Incorporated
2/21/2016
7
How fast do you need the
data?
March 22, 2016
Aerial photograph of Manhattan, NY. Sept 12, 2001
Wikipedia, source NASA
13©TSI Incorporated
Do we evacuate or shelter?
This image cannot currently be displayed.
March 22, 2016
U.S. Air Force photo/Master Sgt. Wally Baciohttps://www.flickr.com/photos/chucksimmins/2857833739
14©TSI Incorporated
2/21/2016
8
Real Time Aerosol Measurement
Instruments
March 22, 2016
+ Beta Attenuation Monitor (BAM)
+ Tapered Element Oscillating Microbalance (TEOM)
+ Piezoelectric Microbalance
+ Aerodynamic Particle Sizer (APS)
+ Differential Mobility Analyzer Spectrometer (DMS)
+ Integrating Nephelometer (Photometer)
+ Condensation Particle Counter (CPC)
+ Optical Particle Counter (OPC)
15©TSI Incorporated
“IH-based” field instruments
+ Photometers
+ Optical Particle Counters
+ Condensation Particle Counters
March 22, 2016
DustTrak™ DRX 8533Photometer
AeroTrak® 9306 OPC
P-Trak® 8525CPC
16©TSI Incorporated
2/21/2016
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Light Scattering Photometer
Technology
PhotoDetector
Laser Diode
Light Trap
Aerosol Inlet
Sheath Air
Mirror
Gravimetric Filter
Beam Shaping
OpticsViewing Volume
OpticsChamber
Orifice
HEPA Filter
Exhaust
Flowmeter
Pump
ProtectionFilter
Dampening
Chamber
Laser
Beam
17
8533 DustTrak™ DRX
March 22, 2016©TSI Incorporated
Optical Particle Counter (OPC)
Optical Particle Counter (OPC) – light scattered by
individual particles traversing a light beam is detected at
various angle. These signals are interpreted in terms of
particle size via calibrations.
March 22, 2016 18©TSI Incorporated
2/21/2016
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Condensation Particle Counter (CPC)
Three Basic Components
3. Optics
Each particle passes through a laser,
scattering light
Each light scatter pulse is counted
2. Condenser
Cooled to condense vapors onto
particles, particles grow
1. Saturator
Heated to saturate sample with
isopropanol vapor
2
1
3
March 22, 2016 19©TSI Incorporated
How these instruments work
March 22, 2016 20©TSI Incorporated
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Physics of aerosols
+Properties
+Behavior
+Measurements
Aerosol Basics
March 22, 2016 21©TSI Incorporated
Aerosol Characteristics
March 22, 2016
+Size
+Shape
+Density
+Refractive Index
+Size Distribution
22©TSI Incorporated
2/21/2016
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Aerosol properties
March 22, 2016
+ Aerosols absorb, reflect, refract and diffract light
+ Light passing through an aerosol concentration is
affected by the properties of the aerosol.
23©TSI Incorporated
Particle counting vs. light scattering
March 22, 2016
+ Particle counting is like
counting the number of
rain drops or snow flakes
that hits the window
+ OPCs count the number of
raindrops (or snow flakes)
hitting the windshield.
+ CPCs count the number of
ultrafine particles
24©TSI Incorporated
2/21/2016
13
+ Photometers measure the
amount of light scattered
by the fog.
+ “thicker fog” is brighter.
Photometric light scattering
March 22, 2016 25©TSI Incorporated
Calibration aerosol
March 22, 2016
+ Photometers are
calibrated to a test
aerosol with known
properties
+ A bucket of golf balls will
not weigh the same as a
bucket of ping pong balls.
26©TSI Incorporated
2/21/2016
14
+ Calibration factors adjust
the instrument response
to the difference between
the sampled aerosol and
the test aerosol.
+ Size
+ Shape
+ Density
+ Refractive Index
+ Size Distribution
Calibration factor
March 22, 2016 27©TSI Incorporated
Aerosol concentration
measurement range
Photometers Optical Particle
Counters
Condensation
Particle Counters
0.001 to 400
mg/m3
0 to 70
particles/cm3
0 to 500,000
particles/cm3
March 22, 2016 28©TSI Incorporated
2/21/2016
15
0.001 0.01 0.1 1 10 100Particle Size Range (micrometers)
Inhalable
(Total dust)
TSPRespirable
Thoracic Particle Size Range for
Aerosol Instruments
Photometer
CPC-alcohol
OPC
Diffusion Charger
4
Photometer: 0.1 to 15 µm
Optical Particle Counter 0.3 to 25 µm
Condensation Particle Counter 0.02 to 1 µm
CPC - Water
SMPS
Nanoparticle
March 22, 2016 29©TSI Incorporated
Aerosol Size Distribution
March 22, 2016
+ A photometer ‘sees’ aerosols
of all shapes and sizes
+ The photometer measures the
light scattering of these
particles as a group.
+ Mass is calculated based on
the properties of the
calibration aerosol.
Fly ash – FHWA.dot.gov
30©TSI Incorporated
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Strengths and limitations of
photometers
March 22, 2016 31©TSI Incorporated
Limitations
+ Calibrated to test aerosol
+ Humidity effects
+ Contaminated optics
March 22, 2016 32©TSI Incorporated
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Calibrated to test aerosol
+ Precise instrument response to all aerosol
+ Response to aerosol similar to calibration
aerosol will more closely match actual
gravimetric result
+ Use side-by-side gravimetric results to develop
custom calibration factors (K factors)
March 22, 2016 33©TSI Incorporated
Diesel Particulate Matter
Photometer Correction FactorUniversity of Utah Study
+ Compare DustTrak 8020 to
NIOSH 5040 sampling
results for DPM.
+ 7 trips to underground
hard rock mines in Utah
and 3 trips in Montana
K factor = (gravimetric mass) / (photometric measurement)
Gravimetric DustTrak K factor
µg/m3 µg/m3
170 245.9 0.691
208.1 214.6 0.970
311.4 363.2 0.857
263.9 438.3 0.602
1214.4 2220.6 0.547
353.6 508.8 0.695
115.1 336.7 0.342
23.8 57.3 0.415
19.8 71.4 0.277
46.7 80.8 0.578
AVG K factor 0.597
March 22, 2016 34©TSI Incorporated
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Diesel Particulate Matter
Photometer Correction FactorUniversity of Utah Study
y = 1.3x + 0.36
R² = 0.95 P <0.001
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
0.000 2.000 4.000 6.000 8.000 10.000 12.000
Fil
ter
Con
cen
trati
on
(m
g/m
3)
Direct Read Instrument Concentration (mg/m3)
DustTrak concentration readings are highly correlated to filter concentration measurements.
March 22, 2016 35©TSI Incorporated
Diesel Particulate Matter
Photometer Correction FactorCustomer data
Gravimetric DustTrak K factor
µg/m3 µg/m3
49 152 0.322
82 362 0.227
52 82 0.634
100 126 0.794
80 176 0.455
Avg K factor 0.486
K factor = (gravimetric mass) / (photometric measurement)March 22, 2016 36©TSI Incorporated
2/21/2016
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Photometric
Calibration Factor
Factory Calibration 1.0
Respirable Silica (1) 0.712
Wood Smoke (4) 0.64
DPM (1) 0.597
DPM(2) 0.486
Outdoor Ambient
Urban Pollution (3)
0.38
Photometer ‘K-Factors’
(1) University of Utah – Rodney R. Larson, et al.
(2) TSI Metal Mining Customer, 2014
(3) Wallace , et. al, Journal of Exposure Science and Environmental Epidemiology, 2011.
(4) McNamara, et al, Aerosol and Air Quality Research, 11:315-322, 2011.
March 22, 2016 37©TSI Incorporated
Humidity effect
+ Hygroscopic aerosols swell as humidity levels
increase
+ Photometric instrument readings will be
elevated in humid conditions
+ Inlet conditioners to reduce the effects of
humidity are added to photometric instruments
for long term environmental monitoring
March 22, 2016 38©TSI Incorporated
2/21/2016
20
Optic contamination
+ High aerosol levels can result in contaminated
optics and measurement drift
+ Zeroing the instrument regularly helps correct
+ Use size selective inlet conditioners to sample
only small size fractions
March 22, 2016 39©TSI Incorporated
Strengths
+ Consistent measurement
+ Real-time
+ Data logging
+ Alarms
March 22, 2016 40©TSI Incorporated
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Consistent MeasurementPerformance: DustTrak™ DRX VS TEOM
TSI Application Note EXPMN-004
March 22, 2016 41©TSI Incorporated
Real time data
March 22, 2016
“How far down wind do we need to evacuate people?”
42©TSI Incorporated
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Data loggingPeaks
Avg = 0.176 mg/m3
Max = 1.11 mg/m3
What caused this spike?
Customer data
March 22, 2016 43©TSI Incorporated
Data loggingHistorical Trends
March 22, 2016
0
0.1
0.2
0.3
0.4
0.5
0.6
0 5 10 15 20 25 30 35 40 45 50
mg
/m
3
Days
Daily average dust levels
44©TSI Incorporated
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Alarms
+ Audible or visual notification at selected levels.
+ Stop the work and adjust engineering controls
+ Prevents exposure, prevents complaints
March 22, 2016 45©TSI Incorporated
Application Examples
March 22, 2016 46©TSI Incorporated
2/21/2016
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Optical Particle CounterClean Room Certification
March 22, 2016
NASAhttps://commons.wikimedia.org/wiki/File:MSL_R
over_Environmental_Monitoring_Station.jpg
+ FED-STD 209E
+ ISO 14644-1
Cleanroom
Classification
+ Number of particles
of various size per
unit volume
47©TSI Incorporated
Mining+ Organization has
characterized site aerosol
exposures and developed
custom calibration factors
for silica.
+ Miners wear personal
aerosol monitors on a
regular basis to track silica
exposure levels.
Photometer Personal monitoring
March 22, 2016 48©TSI Incorporated
2/21/2016
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+ Handheld photometer
used to measure
ambient smoke levels
for worker safety during
regional forest fires
49
PhotometerAmbient smoke from forest fire
March 22, 2016
Alberta, Canada
49©TSI Incorporated
PhotometerDust storm & wild fire alerts
50March 22, 2016
Australian Outback
50©TSI Incorporated
2/21/2016
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PhotometerFence Line Monitoring - Construction
51March 22, 2016
Meadowlands Stadium - New Jersey
51©TSI Incorporated
PhotometerTrack Smoke Plumes
+ Protect Firefighters &
Clean Up Crew Health
+ Quantify particle mass
exposures to help EPA
reporting
52March 22, 2016
Gulf of Mexico
52©TSI Incorporated
2/21/2016
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PhotometerAmbient urban pollution
March 22, 2016 53©TSI Incorporated
+ Track wind, weather and aerosol
concentration
+ Logging data for community awareness
+ Action level for dust suppression
activities
PhotometerPerimeter monitoring - Mining
March 22, 2016 54©TSI Incorporated
2/21/2016
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PhotometerControl Verification
March 22, 2016
0
0.5
1
1.5
2
2.5
8:0
0
8:3
0
9:0
0
9:3
0
10
:00
10
:30
11
:00
11
:30
12
:00
12
:30
13
:00
13
:30
14
:00
14
:30
15
:00
15
:30
16
:00
mg
/m
3
Time
Simulated Personal Exposure
Data
+ Engineering control investment (ventilation)+ One person sampled high for silica on follow up
Foundry ventilation project
55©TSI Incorporated
PhotometerSpace Station Air Quality
+ TSI DustTrak™ used on
International Space
Station to monitor air
quality
56March 22, 2016©TSI Incorporated
2/21/2016
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Condensation Particle CounterFire Detection in Space Shuttle
+ TSI P-Trak® ultrafine
particle counter used on
NASA Space Shuttles for
smoke/fire detectors
57March 22, 2016©TSI Incorporated
+ Measure ultrafine
particles leaking into the
mask.
+ Fit factor is calculated by
difference between
ambient aerosol particle
counts and particle
counts inside mask.
Condensation Particle CounterRespirator Fit Testing
March 22, 2016
8038 PortaCount® Pro+
58©TSI Incorporated
2/21/2016
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+ Nurses on floor above
construction complaining
of odors and headaches.
+ High concentration of
ultrafine particles found
coming through expansion
joint.
+ Duct Tape applied to joint,
complaints ceased.
Condensation Particle CounterIAQ complaints
March 22, 2016 59©TSI Incorporated
+ Solid particle number
concentration downstream
of the Diesel Particulate
Filter must be below
250,000 particles/cc
+ Swiss Regulation 941.242
Condensation Particle MonitorDiesel Particulate Filter Testing
March 22, 2016 60©TSI Incorporated
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+ Particulates
• Elemental carbon
• Organic compounds
• Sulfate
• Nitrate
+ Gases
• Carbon monoxide
• Carbon dioxide
• Sulfur
• Nitrogen oxides
• Aldehydes
• Benzene
• Polyaromatic hydrocarbons
Diesel Particulate Matter
“Most diesel exhaust particles are tiny enough to
be inhaled deep into the lungs where they pose
significant health risk.”Workers Health and Safety Centre Federation of Ontario
March 22, 2016 61©TSI Incorporated
Kittelson, Journal of Aerosol Science, 1998
Typical engine exhaust particle
size distribution
March 22, 2016 62©TSI Incorporated
2/21/2016
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MSHA DPM Exposure Limits Date Limit
mg/m3
Constituent Interim / Final
2001 0.4 TC Interim (not enforced)
2003 0.4 TC Interim (enforced)
2006 0.308 EC Interim
2007 0.350 TC Interim
2008 0.160 TC Final
TC = Total Carbon
EC = Elemental Carbon
Controlling Diesel Emissions in Underground Mining within an Evolving
Regulatory Structure in Canada and the United States of America, S. McGinn,
McGinn Integration Inc.
March 22, 2016 63©TSI Incorporated
Reducing Particulate Matter Emitted by
Engines
+ Very low particulate matter emission limits are
challenging to measure accurately
March 22, 2016 64©TSI Incorporated
2/21/2016
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+ Bi-annual testing of Non-Road Mobile Machinery
+ Solid particle number concentration downstream of the
Diesel Particulate Filter must be below 250,000
particles/cc
+ Regulation promulgated January 1, 2015, enforcement
begins April 1, 2017
Swiss Regulation 941.242
March 22, 2016 65©TSI Incorporated
Summary
+ Occupational health compliance based on
Gravimetric Sampling
+ Real-Time Aerosol Monitors can help make faster
decisions
+ Logged Data can display trends to help identify
problems not measured with gravimetric
sampling
March 22, 2016 66©TSI Incorporated
2/21/2016
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March 22, 2016
Ultrafine particles
+ high number concentration
+ very low mass
Swiss Regulation 941.242
+ Solid particle number concentration downstream of the Diesel
Particulate Filter must be below 250,000 particles/cc
+ Future occupational health metrics?
Something to consider
67©TSI Incorporated
Q & A
Scott Norman, CIH, CSP
Product Specialist
TSI Incorporated
Shoreview, MN
(651) 490-2702
March 22, 2016 68©TSI Incorporated
2/21/2016
35
Appendix
Beta Attenuation Monitor (BAM)
The schematic of a beta attenuation
monitor (BAM).
1 – air inlet
2 – cycling ribbon
3 and 4 – beta radiation sources;
D1 and D2 – beta radiation detectors
5 – air pump
6 – air exhaust
Source: Wikipedia
March 22, 2016 70©TSI Incorporated
2/21/2016
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Beta Attenuation Monitor (BAM)
+ Beta Attenuation Monitor (BAM) – This methodology collects
particulate mass on a filter tape. Beta rays from a radiation source
are attenuated according to a function of particulate mass. First the
attenuation is measured through the blank filter tape to establish a
baseline. Then the filter tape is exposed to ambient air flow to
deposit particulate matter on the tape. Then beta attenuation is
measured through the collected aerosol deposit and the effect due to
particulate mass is calculated. The instrument advances the filter
tape and repeats the process.
March 22, 2016 71©TSI Incorporated
Tapered Element Oscillating
Microbalance (TEOM)
+ Tapered Element Oscillating Microbalance (TEOM) – This
methodology continuously collects particles on a filter mounted on the
tip of a glass element which oscillates in an applied electric filed. The
glass element is hollow with the wider end fixed. Air is drawn through
the filter and element. The oscillation frequency of the glass element is
maintained based on the feedback signal from an optical sensor. The
resonant frequency of the element decreases as mass accumulates on
the filter, directly measuring inertial mass. Typical signal averaging
period is 5 minutes.
March 22, 2016 72©TSI Incorporated
2/21/2016
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Piezoelectric Microbalance
+ Piezoelectric Microbalance – This methodology deposits particles by inertial
impaction or electrostatic precipitation onto the surface of a piezoelectric
quartz crystal disk. The natural resonant frequency of the crystal decreases as
particle mass accumulates. The changing frequency of the sampling crystal is
electronically compared to a clean reference crystal, generating a signal that is
proportional to the collected mass.
March 22, 2016 73©TSI Incorporated
Integrating Nephelometer+ Integrating Nephelometer - This methodology focuses aerosol through an
optics chamber where light (usually from a laser) is shined at the airstream
containing the particles. An optical sensor measures the intensity of the light
scattered by the particles. Aerosol mass is calculated based on the reflected
intensity of a known calibration aerosol. TSI Model 3563 is an integrating
NEPHELOMETER.
March 22, 2016 74©TSI Incorporated
2/21/2016
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Aerodynamic Particle Sizer
(APS)Aerodynamic Particle Sizer –
This methodology uses parallel
laser beams to measure the
velocity lag of particles
suspended in accelerating air
flows. The TSI Model 3321 APS
uses this technology.
March 22, 2016 75©TSI Incorporated
Condensation Particle Counter
(CPC)
Condensation Nuclei Counter
(aka Condensation Particle
Counter) – This methodology uses
a condensing liquid (alcohol or
water) to grow the particle size
large enough to be counted
optically. These instrument s
count numbers of particles, not
mass concentration. The TSI
PortaCount and P-Trak use this
technology.
March 22, 2016 76©TSI Incorporated
2/21/2016
39
Differential Mobility Analyzer – Spectrometer
(DMS)
Differential Mobility
Analyzer- Spectrometer –
Particles are classified
according to their mobility
in an electric field, which is
a function of their size. A
condensation nuclei
counter then counts the
population in a size “bin.”
The TSI SMPS 3938 uses a
Differential Mobility
Analyzer to separate out
particle size.
March 22, 2016 77©TSI Incorporated
Optical Particle Counter
(OPC)Optical Particle Counter (OPC) – light scattered by individual particles
traversing a light beam is detected at various angle. These signals are
interpreted in terms of particle size via calibrations. The TSI Aerotrak
Handheld Particle Counter 9303 and 9306 use this technology.
March 22, 2016 78©TSI Incorporated