real time dust monitoring strategies and tools€¦ · light scattering photometer technology photo...

2/21/2016

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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

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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


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+ Dust

+ Fume

Aerosol


+ Dust

+ Fume

+ Mist

Aerosol


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+ Dust

+ Fume

+ Mist

+ Smoke

Aerosol


Aerosol Size Matters


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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

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+ Pump

+ Sampling Cassette

+ Media

+ Cyclone

+ Tubing

Pump

Measurement of Aerosols

Traditional IH Air Sampling

Equipment


+ 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


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How fast do you need the

data?

March 22, 2016

Aerial photograph of Manhattan, NY. Sept 12, 2001

Wikipedia, source NASA


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


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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)


“IH-based” field instruments

+ Photometers

+ Optical Particle Counters

+ Condensation Particle Counters

March 22, 2016

DustTrak™ DRX 8533Photometer

AeroTrak® 9306 OPC

P-Trak® 8525CPC


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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.


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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


How these instruments work


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Physics of aerosols

+Properties

+Behavior

+Measurements

Aerosol Basics


Aerosol Characteristics

March 22, 2016

+Size

+Shape

+Density

+Refractive Index

+Size Distribution


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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.


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


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+ Photometers measure the

amount of light scattered

by the fog.

+ “thicker fog” is brighter.

Photometric light scattering


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.


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+ 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


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


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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


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


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Strengths and limitations of

photometers


Limitations

+ Calibrated to test aerosol

+ Humidity effects

+ Contaminated optics


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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)


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


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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.



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

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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.


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


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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


Strengths

+ Consistent measurement

+ Real-time

+ Data logging

+ Alarms


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Consistent MeasurementPerformance: DustTrak™ DRX VS TEOM

TSI Application Note EXPMN-004


Real time data

March 22, 2016

“How far down wind do we need to evacuate people?”


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Data loggingPeaks

Avg = 0.176 mg/m3

Max = 1.11 mg/m3

What caused this spike?

Customer data


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


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Alarms

+ Audible or visual notification at selected levels.

+ Stop the work and adjust engineering controls

+ Prevents exposure, prevents complaints


Application Examples


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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


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


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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


PhotometerDust storm & wild fire alerts

50March 22, 2016

Australian Outback


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PhotometerFence Line Monitoring - Construction

51March 22, 2016

Meadowlands Stadium - New Jersey


PhotometerTrack Smoke Plumes

+ Protect Firefighters &

Clean Up Crew Health

+ Quantify particle mass

exposures to help EPA

reporting

52March 22, 2016

Gulf of Mexico


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PhotometerAmbient urban pollution


+ Track wind, weather and aerosol

concentration

+ Logging data for community awareness

+ Action level for dust suppression

activities

PhotometerPerimeter monitoring - Mining


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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


PhotometerSpace Station Air Quality

+ TSI DustTrak™ used on

International Space

Station to monitor air

quality

56March 22, 2016©TSI Incorporated

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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+


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


+ 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


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+ Particulates

• Elemental carbon

• Organic compounds

• Sulfate

• Nitrate

+ Gases

• Carbon monoxide

• Carbon dioxide

• Sulfur

• Nitrogen oxides

• Aldehydes

• Benzene

• Polyaromatic hydrocarbons


“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


Kittelson, Journal of Aerosol Science, 1998

Typical engine exhaust particle

size distribution


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.


Reducing Particulate Matter Emitted by

Engines

+ Very low particulate matter emission limits are

challenging to measure accurately


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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


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


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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


Q & A

Scott Norman, CIH, CSP

Product Specialist

TSI Incorporated

Shoreview, MN

(651) 490-2702

[email protected]


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


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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.


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.


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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.


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.


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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.


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.


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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.


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.


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