1. Continuous PM2.5 Monitoring
Washington State

2. Continuous PM2.5 Monitoring
Devices used in Washington
Nephelometers
Tapered Element Oscillating Microbalances (TEOM)
Beta Attenuation Monitors (BAM)
Aethalometers

3. Continuous PM2.5 Monitoring
Nephelometers are in the majority (50)
TEOM’s (15) & BAM’s (4) are next
Aethalometers are typically collocated with another continuous device (10 )

4. Continuous PM2.5 Monitoring
Why nephelometers?
Dependable & reliable
Easy to operate
Function well in all parts of the state
Correlate well with FRM
Currently cost effective VS other devices

5. Continuous PM2.5 Monitoring
Why nephelometers? Cont.
Provide geographic representation for public health
AQI

6. Continuous PM2.5 Monitoring
Any down side to nephelometers?
Acquisition of parts & service from the current vendor can be time consuming
Not an equivalent method – current vendor may never be

7. Continuous PM2.5 Monitoring
The future of nephelometers in Washington:
Short term - press on, business as usual
Long term - serviceability questions and potential problems with equivalency

8. Continuous PM2.5 Monitoring
Planned future work:
Look at other continuous monitoring options, new vendors
Model confirmation – returning to locations to run short term and seasonal correlation verification
Develop models outside of the current, year-round look
Automation of zero & spans to reduce operator trips to remote sites