continuous ambient particulate monitors a review of current technologies l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Continuous Ambient Particulate Monitors A Review of Current Technologies PowerPoint Presentation
Download Presentation
Continuous Ambient Particulate Monitors A Review of Current Technologies

Loading in 2 Seconds...

play fullscreen
1 / 37

Continuous Ambient Particulate Monitors A Review of Current Technologies - PowerPoint PPT Presentation


  • 285 Views
  • Uploaded on

Continuous Ambient Particulate Monitors A Review of Current Technologies. by Michael Corvese, Product Manager Thermo Electron Corporation Air Quality Instruments. Aerosol Monitoring. Aerosol Characteristics Health effects Regulatory Background Sampling & Analysis Regulatory Developments.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Continuous Ambient Particulate Monitors A Review of Current Technologies' - johana


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
continuous ambient particulate monitors a review of current technologies

Continuous Ambient Particulate MonitorsA Review of Current Technologies

by

Michael Corvese, Product Manager

Thermo Electron Corporation

Air Quality Instruments

aerosol monitoring
Aerosol Monitoring
  • Aerosol Characteristics
  • Health effects
  • Regulatory Background
  • Sampling & Analysis
  • Regulatory Developments
aerosol characteristics
Aerosol Characteristics

DEFINITION

Aerosol – small solid or liquid particles suspended in gas

  • Dust from nature, wind, human activity (pollen, road dust fly ash)
  • Fog from heating/cooling (clouds and fog)
  • Mist from atomization and nebulizer (sulfuric acid mist)
  • Spray from ultrasonics (insecticide spray)
  • Smoke from combustion or flame (cigarette, soot, diesel)
  • Smog from photochemicals (Urban Smog)
aerosol characteristics4
Aerosol Characteristics

• Physical characteristics

Size distribution

Shape

Refractive Index

Concentration (mass or number)

• Chemical characteristics

Composition (chemical or elemental)

Acidity/alkalinity

• Temporal characteristics

Chemical and physical characteristics changing with time

• Spatial characteristics

Characteristics changing with location

physical characteristics
Physical Characteristics

SIZE, SHAPE, and REFRACTIVE INDEX

  • 0.002-100µm aerosol research;
  • 0.1-100µm common sampling (0.1-10 mm)
  • Size:
  • Shape:
  • Refractive Index:
  • Many irregular shapes;
  • aerodynamic diameter emphasized
  • Wide range;
  • most consistent below 2.5mm
physical characteristics6
Physical Characteristics

PM10

(10 mm)

PM2.5

(2.5 mm)

Hair cross section (60 mm)

Human Hair

(60 mm diameter)

health effects
Health Effects
  • Health effects are significant
  • Body of evidence is substantial
health effects9
Health Effects

Increased hospital admissions and emergency room visits during high PM conditions

  • Aggravated asthma
  • Chronic bronchitis
  • Increase in respiratory symptoms
  • Decreased lung function
  • Premature death
regulatory background
Regulatory Background
  • 1971—Promulgation of National Ambient Air Quality Standards (NAAQS) for SO2, NO2, O3, CO, and total suspended particulates (TSP)
  • 1978—Promulgation of particulate Pb standard
  • 1987—Promulgation of PM10 standard
  • 1997—Promulgation of revised PM10 standard and

introduction of PM2.5 standard (also a revision of

the O3 standard)

regulatory background12
Regulatory Background

U.S. National Ambient Air Quality Standards (NAAQS)

sampling and analysis
Sampling and Analysis
  • High volume methods: TSP, PM10, PM2.5, Air Toxics Sampler (PUF)
  • Low volume methods: (PM10, PM2.5, PMCoarse)

Common Gravimetric Ambient Aerosol Sampling Techniques

(Gross - Tare) / Air Volume = mg/m3

sampling and analysis14
Sampling and Analysis

High Volume Methods: TSP and PM10 Samplers

sampling and analysis15
Sampling and Analysis

Low Volume Methods

PM10/PM2.5 FRM & PMc/PM2.5 Dichotomous Sampler

sampling and analysis16
Sampling and Analysis

Common Gravimetric Ambient Aerosol Sampling Techniques

(Gross - Tare) / Air Volume = mg/m3

  • Advantages: Recognized reference method, low capital cost
  • Disadvantages: Limited time resolution (typically 24-hr), long turnaround times, labor intensive, and gravimetric lab maintenance/cost
sampling and analysis17
Sampling and Analysis

Common Continuous Ambient Aerosol Sampling Techniques

(Dm / Dt) / (DV / Dt) = mg/m3

  • Light Scattering, Absorption, and Extinction
  • Tapered Element Oscillating Microbalance
  • Beta (Electron) Attenuation
  • Hybrid Methods
sampling and analysis18
Sampling and Analysis

Impaction Separation

Cyclone Separation

Cut Point

100%

Eficiency

50%

0%

PM100

PM1.0

PM10

sampling and analysis19
Sampling and Analysis
  • Advantages: Low operational cost, better time resolution, increased statistical database, instantaneous turnaround (index reporting, increased knowledge of air shed characteristics)
  • Disadvantages: 2-3x capital cost, limited reference capabilities (pending USEPA & CASAC Guidelines)

Common Continuous Ambient Aerosol Sampling Techniques

(Dm / Dt) / (DV / Dt) = mg/m3

sampling and analysis21
Sampling and Analysis

Continuous Methods

  • Light Scattering: Excellent time resolution; limited by refractive index and aerosol distribution (particle size)
  • Oscillation Frequency Measurement: Good time resolution, seasonal & regional performance issues
  • Beta (Electron) Attenuation: Proven technology, minimal performance issues, versatile
sampling and analysis23
Advantages

Continuous method

Highly time resolved

High resolution

Disadvantages

Temperature dependency

Affected by vibration

Manual filter changes necessary

Seasonal and regional dependencies

Complex systems require some skill

Volatile losses

Sampling and Analysis

Other Technologies

Oscillation Frequency Measurement

series fh 62 c14 features and benefits
Series FH 62 C14Features and Benefits

Mean NH

NO

-Loss l

due to heated suction tube

4

3

m

10%

0%

-10%

m

l

-20%

-30%

t

t

=

* exp(E / k

T)

0

B

t

t

l

=

/t * (1 - exp(-t/

)) - 1

-40%

m

-50%

10

20

30

40

50

60

70

80

J

in °C

Fixed heating w/auto filter changes

is an improvement over long term heating on fixed spot.

Heating Considerations

Actual and mean VOC

loss (l and l

) due to

m

heated sample area at 50°C

0%

m

-20%

) loss l and l

-40%

3

NO

-60%

4

l

m

VOC(NH

-80%

l

-100%

0

5

10

15

20

25

30

t in days

b attenuation principle of operation
b AttenuationPrinciple of Operation
  • Constant flow of aerosol is metered and sampled onto a filter stain area.
  • The detection of Beta Attenuation is proportional to increased mass.
  • Every 1-24 hrs a new filter area is zeroed and introduced.
sharp monitor principle of operation
SHARP MonitorPrinciple of Operation
  • Combination nephelometer + beta attenuation
  • High sensitivity light scattering photometer is continuously calibrated by an integral time averaged beta attenuation mass sensor
  • Measured mass concentration remains independent of changes in the particle population being sampled
sampling and analysis27
Sampling and Analysis

b Attenuation Technology

  • Ambient inlet
  • Sensing volume
  • b Source & detector

Direct b Attenuation

  • Advantage
  • Truly continuous
  • Non-intrusive
  • Disadvantage
  • No known manufacturers
  • Poor detection limit
  • Requires very high concentrations
sampling and analysis28
Sampling and Analysis

b Attenuation Technology

  • Ambient Inlet
  • Sensing Volume
  • β Source & detector
  • Filter tape

Stepwise b Attenuation

  • Advantage
  • Semi-continuous
  • Sound technology
  • Good hourly precision
  • Disadvantage
  • Semi-continuous
sampling and analysis29
Sampling and Analysis

b Attenuation Technology

  • Ambient inlet
  • Sensing volume
  • b Source & detector
  • Filter tape

Continuous β-Attenuation

  • Advantage
  • Continuous
  • Sound technology
  • Significant loading for post-collection analysis
  • Disadvantage
  • Potential extended sample loss
sampling and analysis30
Sampling and Analysis

Hybrid Technology

  • Ambient inlet
  • Sensing volume
  • b Source, detector, nephelometer
  • Filter tape

Continuous SHARP Monitor

  • Advantage
  • Truly continuous
  • Low detection limits
  • High time resolution
  • Intelligent moisture control
  • Disadvantage
  • None
b attenuation
b Attenuation

Refined Mass Measurement via Dual Detector

b attenuation33
b Attenuation

Refined Mass Measurement via Dual Detector

  • A dual (a.k.a. proportional) detector allows the daughter nuclides of Radon gas to be measured and accounted for as a mass refining step.
  • This allows the C14 BETA to be consistently stable at lower ambient concentrations.
  • Important for PM2.5
continuous particulate monitors applications
Continuous Particulate MonitorsApplications
  • NAAQS Monitoring
  • AQ Index Reporting
  • Fenceline Monitoring
  • Clean-up Sites

Ambient

In R&D …

  • Unrivaled short-term detection limits/timeresolution
regulatory developments
Regulatory Developments
  • 1997—promulgation of PM2.5 and revision of PM10
  • 1998—PM2.5 standard challenged in court
  • 1999—US Court of Appeals remanded PM2.5

standard back to EPA for revision

  • 2001—US Supreme Court decision

- EPA has the right to promulgate a PM2.5 standard

- Compliance costs should not be considered

- PM Coarse should replace PM10

  • 2005- Proposed revision of PM2.5 expected
  • 2006-Final PM2.5 and proposed PM Coarse regulation expected
continuous particulate monitors
Continuous Particulate Monitors

The End

Thank you for your time and attention