2009 National Ambient Air Monitoring Conference

Continuous PM Mass Instrument

MONDAY, NOVEMBER 2, 2009 –TRAINING SESSIONS

Grimm Model 180

Using Optical Technology

A look at

the technology

used in the

GRIMM 180

2009 National Ambient Air Monitoring Conference

Main principles of optical particle detection

Components Main FunctionSample air inlet Reproducibility

Sample air pump Constant flow rate

Light source Generating a signal

Well defined optical volumeOptical Beam

Light trap Eliminate signal noise

Detection optic Known aperture / backward, forward, 90°optical or aerodynamic focusing

Detector scattering light / photo diode, multiplierSignal processing& data processing

rapid count processing andaccurate size classification

All components together determine the spectrometersAll components together determine the spectrometerscounting efficiency (coincidence concentration)counting efficiency (coincidence concentration)

and sizing accuracy (particle size resolution) and sizing accuracy (particle size resolution)

Basic Principles of Particles DetectionThe Nephelometer

x

y

y

aerosol particles

detection volume

Signal from agroupgroup of particles!

Light source

Detector

Sample in

Advanced principles of particle detectionSpectrometer with 90° detection

y

90°x

yzaerosol particles

aerosol focusingdetection volume

Signal from eachsinglesingle particle!

Light source

Detector

Sample in

Light trap

GRIMM can do it !!! GRIMM can do it !!!

Single Particle Light ScatteringGrimm Spectrometer Principle

aerosol focusingaerosol focusing

Single Particle Light ScatteringGrimm Spectrometer Principle

Pump

Laser

Sample stream with particles

Particle filterMeasuringchamber

PTFE-Filter

Light trap

Clean air

Sheath Air to protect Optics

Outlet

Purge air

Sheath air

Particle count distribution is the base for the dust mass calculation. We convert these optical count values to a mass distribution. The geometric mean value between two thresholds of each of the 31 different channels is multiplied by a densityfactor corresponding to the established “urban environment”factor. With this implementation we obtain the proper mass distribution over the full range. Finally we needs to correlate the sample air volume to the mass value to obtain mass/volume.

Mass Distribution Determination & PM Calculation

Based on the obtained mass distribution we can now implement the cut points of the sampling heads. The PM10, PM2.5 and PM1 are then applied.

Grimm Model 180

Candidate forUS EPA PM 2.5Class III FEM

Approval

US EPA PM 2.5 Class III FEM Approval

A: Bakersfield, CA

B: Denver, CO

C: St. Louis, MI

D: New Haven, CT

A: Winter & Summer (46 days)

B & C: Winter Only (23 days each)

D: Summer Only (23 days)

GRIMM Test Sites for Class III Continuous Monitors

Our choice of reference instrument:Our choice of reference instrument:

US EPA PM 2.5 Class III FEM Approval

Grimm Trailer

US EPA PM 2.5 Class III FEM Approval

Grimm Trailer

Results Bakersfield – Scatter Plots

Bakersfield Sitey = 0.977x - 0.079

R2 = 0.9812

3

13

23

33

43

53

63

73

83

3 13 23 33 43 53 63 73 83

FRM (ug/m3)

Gri

mm

180

(ug/

m3)

Results Bakersfield – Time Series

Bakersfield Site

3

13

23

33

43

53

63

73

83

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45

DAY

Conc

entra

tion

(ug/

m3)

FRMGrimm 180

Results Denver – Scatter Plots

Denver Site y = 0.965x + 0.0939R2 = 0.966

3

8

13

18

23

28

3 8 13 18 23 28

FRM (ug/m3)

Grim

m 1

80 (u

g/m

3)

Results Denver – Time Series

Denver Site

3

8

13

18

23

28

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29

DAY

Conc

entra

tion

(ug/

m3)

FRMGrimm 180

Results St-Louis – Scatter Plots

St-Louis Site y = 0.9936x + 0.1815R2 = 0.9466

3

8

13

18

23

28

33

38

3 8 13 18 23 28 33 38

FRM (ug/m3)

Grim

m 1

80 (u

g/m

3)

Results St-Louis – Time Series

St-Louis Site

3

8

13

18

23

28

33

38

1 3 5 7 9 11 13 15 17 19 21 23 25

DAY

Con

cent

ratio

n (u

g/m

3)

FRMGrimm 180

Results New Haven – Scatter Plots

New Haven Sitey = 0.9664x + 0.0377

R2 = 0.9139

3

5

7

9

11

13

15

17

19

3 5 7 9 11 13 15 17 19

FRM (ug/m3)

Gri

mm

180

(ug/

m3)

Results New Haven – Time Series

New Haven Site

3

5

7

9

11

13

15

17

19

1 3 5 7 9 11 13 15 17 19 21 23 25

DAY

Conc

entra

tion

(ug/

m3)

FRMGrimm 180

Results Summary

Bakersfield Denver

St-Louis New Haven

The Grimm 180 can operate for one year un-attended.Annual Calibration at Grimm USA Office.On-site audits can be easily achieved with the compact Test-Kit available.

Flow CheckLeak-TestZero Particle Test

Operation & Maintenance

CALIBRATION TOWER

Benefit of the technology

No Consumable

Minimal Maintenance

Real-Time Measurement (6 sec)

PM2.5 + PM10 + PMc with a single instrument

Insensitive to vibration → Mobile Application

Easy Installation

Come to our booth for more

information.