# Presentation: 374044

## EPA  NAQC 2005   San Francisco, CA

**From Nanograms to Milligrams:**
**The Aethalometer**TM** AE-90**
**for direct Tailpipe Emissions Measurement **
**of Carbonaceous Aerosol Particles**
- Tony Hansen
- Magee Scientific Company
- Berkeley, CA

## Diesel Exhaust    -   Listed Air Toxic

- Toxic Components : ***Specific Compounds ***require ***Specific Chemical Analyses***
- Accompanying components may permit more rapid detection by optical means:
- 	***Black Soot*** and ***UV-Absorbing Material***

## Analytical Premise

- Optically-absorbing material is a         ***surrogate tracer*** for diesel exhaust.
- 	“Black” carbon (‘BC’, ‘EC’)
- 	“UV-absorbing material” (‘UVPM’)
- Optical analysis is fast, sensitive, can be performed in real time or on filter samples.

## Analytical Method  -  Optical Absorption

## Optical vs. chemical analyses

- “Harvard 6 Cities Study”

## Analytical Instrument  :  AethalometerTM

- While continuously collecting sample, measures ***optical absorption*** in real time    at 2 wavelengths (880 nm and 370 nm UV)
- Converts ***optical absorption*** to                   ***mass concentration*** of BC and UVPM
- Real-time data:  1 second / 1 minute / 1 hour

## Analytical Instrument  :  AethalometerTM

- 19-inch rack mount model

## “Portable” AethalometerTM

- Battery-powered: 1-, 2- or 7-wave optics

## Diesel indoors: truck in exhibition hall

## A Diesel Repair Garage ... in Antarctica

## Bus Yard Exhaust - community impact

## On The Bus in Boston

## On The Train in Boston

## Direct Tailpipe Emissions Analysis

_**The Need**_:
- 	On-the-spot analysis for tailpipe BC & UV
_**The Problem**_:
- 	Concentrations are too high for analysis based on continuous collection

## New Instrument:   Aethalometer “Tailpipe Tester”

- Model ‘AE90’:
- Constructed in same chassis, identical optical analysis

## Methodology:

- Pull sample _continuously_ through heated probe inserted into tailpipe.
- Bypass internally until ready for data.
- Switch sample stream through filter spot for a _few seconds only_.
- After collection, dry with warm filtered air.
- Perform optical analysis ‘on the spot’.

## Results :  3 to 15 mg/m3

## Results : 10 to 50 mg/m3

**AE90 prototype ‘tailpipe’ Aethalometer**

**BC (ug/m3)**

**Diesel 3**

**Diesel 2:**
**Higher idle,**
**Load applied**

**Successive Individual Measurements**

## Applications:  Captive fleet testing

- Identify ‘High Emitters’ for remedial action
- Test effectiveness of engine tune-up:
- 	reduce source strength at exhaust manifold
- Test effectiveness of emissions reduction equipment (filters, catalytic converters etc.)
- 	reduce final emissions from tailpipe

## Applications: on-road vehicles

- Spot checks - identify ‘High Emitters’
- Response to complaints
- Test trucks at highway inspection stations
- Routine vehicle testing for annual certification

## Applications: Engine Manufacturers

- Engine R&D testbed measurements
- Real-time response to changing engine operation conditions
- Test effectiveness of fuel additives or downstream emissions clean-up devices

## Summary

***Black Carbon*** and ***UV-Absorbing Carbon*** are good surrogates for diesel exhaust***.***
- The ‘Tailpipe Tester’ **AE-90** Aethalometer uses the established optical analysis method to measure ***BC*** and ***UVPM*** directly in the exhaust stream, ‘on the spot’.

## Acknowledgments

- Harvard School of Public Health
- National Institute of Chemistry, Slovenia
- For further information:
**www . mageesci . com**