CARB Continuous PM 2.5Monitoring Activity

(BAM’s)

Reggie Smith

California Air Resources Board

Continuous PM2.5 Monitor Network

• ARB Ambient Air Monitoring Sites– 13 Sites with BAM-1020 Monitors (17 units)

– 3 Special Purpose Sites (6 units)

– 61 total samplers

• 4 Collocated BAM-1020 Sites

• 9 Sites with FRM and BAM

Standard CARB BAM Configuration

• PM 10 Sampling Inlet (BX-802)

• Sharp Cut Cyclone (BX-807)

• Smart Heater

• Met Translator Option (BX-964)

• Firmware v2.58

• Gast Rotary Pump (BX-121)

• Volumetric Flow Control

Data Analysis

• SLOPE: Indicator of the bias of the BAM compared to the FRM

• INTERCEPT: Offset between the BAM and FRM

• r 2: Correlation coefficient of the linear regression between the two instruments

BAM-1020 Accuracy

Site Slope Intercept r2 % Data Capture Slope Intercept r2 % Data CaptureBakersfield Primary BAM vs. FRM 1.06 5.30 0.920 87 0.950 2.64 0.966 63Bakersfield Collocated BAM vs. FRM 0.858 -4.08 0.920 83 0.998 -1.09 0.959 63Chico Primary BAM vs. FRM 0.855 3.09 0.850 96 1.05 3.74 0.982 98Chico Collocated BAM vs. FRM 0.968 4.63 0.887 97 1.02 3.01 0.991 98Sacramento Primary BAM vs. FRM 1.01 2.76 0.964 99Sacramento Collocated BAM vs. FRM 0.980 3.82 0.940 99Fresno BAM vs. FRM 0.975 6.27 0.881 92 0.998 5.74 0.950 65Visalia BAM vs. FRM 1.00 1.95 0.831 88 1.06 1.32 0.941 73Modesto BAM vs. FRM 1.13 2.71 0.968 96 1.07 1.58 0.983 84Calexico Primary BAM vs. FRM 1.18 3.73 0.788 77 1.21 1.33 0.961 84Calexico Collocated BAM vs. FRM 1.20 3.86 0.877 84 1.17 2.41 0.913 84Roseville BAM vs. FRM 1.05 4.30 0.924 97Yuba City FRM vs. BAM 1.03 1.64 0.923 94

2003 2004

Bakersfield - California Ave.Primary BAM 1020 vs. PM2.5 R&P FRM

6/2004 - 12/2004

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FRM (ug/m3)

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mar

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AM

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Slope: 0.950Intercept: 2.64

r2: 0.966

Bakersfield - California Ave.Collocated BAM 1020 vs. PM2.5 R&P FRM

6/2004 - 12/2004

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FRM (ug/m3)

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AM

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Slope: 0.998Intercept: 1.09

r2: 0.959

BAM-1020 Precision

Site Slope Intercept r2 Slope Intercept r2

Bakersfield BAM vs. BAM 0.991 1.25 0.978 1.01 -3.51 0.964Chico BAM vs. BAM 1.03 2.50 0.963 0.948 -0.298 0.989Sacramento BAM vs. BAM 0.960 1.29 0.956Calexico BAM vs. BAM 0.970 1.58 0.976 0.990 0.906 0.932

2003 2004

Bakersfield California Ave.Primary vs. Collocated PM2.5 R&P FRM

6/1/2004 - 12/31/2004

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Collocated FRM (ug/m3)

Pri

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RM

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Slope: 1.01Intercept: 0.614

r2: 0.985

Bakersfield - California Ave.Primary vs. Collocated BAM 1020

6/1/2004 - 12/31/2004

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Primary BAM (ug/m3)

Co

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d B

AM

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Slope: 1.01Intercept: 3.51

r2: 0.964

Network Summary

• Overall BAM Network Performance– All BAM/FRM data regressed as one data set– Slope of 0.990– Intercept of 3.07

– r2 of 0.940

Overall CARB BAM Network vs. PM2.5 FRM 6/2004-12/2004

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FRM (ug/m3)

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Slope: 0.990Intercept: 3.07r2: 0.940

BAM Maintenance

• Bi-Weekly Leak and Flow Checks are absolutely necessary to ensure proper operation

• Failed leak and flow checks are associated with poor FRM correlation in ARB’s experience

• Adhere to AQSB SOP 400 (BAM Standard Operating Procedures)

CARB Zero Test• Sample Zero air using BX-302 HEPA Filter

• 76 consecutive hours (First 4 hours removed)

• Background set to 0.000

• Min/Max Zero test range of 14 ug/m3

• No value exceeding 20 ug/m3

• Any errors during test, re-run test

• Field zero test annually (24 hour test)

BAM Datalogger Review

• Review of the internal datalogger is important

• Reveals offsets between the BAM and the external data acquisition system

• Review of Qtot (total volume sampled) hourly values helps detect flow problems

• Detailed error codes are stored in the internal datalogger data

Conclusions

• The BAM-1020 Monitor is well-suited for PM-AQI, Prescribed Fire and Ag-Burn Forecasting, diurnal profiling, quantifying short term events, and characterizing atmospheric dynamics

• Is it good enough for regulatory determinations?

Next Steps

• Evaluate data using U.S. EPA’s Criteria Designation of Equivalence Methods forContinuous Surveillance of PM2.5

• Determine how good is good?– Slope: 1.00 +/- 5%– Intercept: 3 ug– Correlation: r2= .940 (r = .97)

Summary

• Contact Information– Voice: (916) 327-1238– E-mail: rsmith@arb.ca.gov

• CARB BAM Website– http://arb.ca.gov/amtac/phpnuke/