1. PM10: Comparison of TEOM-FDMS with Gravimetry
Robert Gehrig, Christoph Hüglin, Beat Schwarzenbach
Swiss Federal Laboratories for Materials Testing and Research
CH-8600 Dübendorf Switzerland

2. TEOM (Tapered Element Oscillating Microbalance)
Source: Baron/Willeke: Aerosol measurement

3. TEOM-FDMS FDMS = Filter Dynamic Measurement System
Compensation for possible
artefacts (humidity and loss
of semi-volatile material)

4. TEOM-FDMS FDMS = Filter Dynamic Measurement System
Compensation for possible
artefacts (humidity and loss
of semi-volatile material)

5. Dübendorf, Evaluation phase, FDMS Type B, 2006/2007

6. Lausanne PM10

7. Lugano (base and reference signal)
○ before spring 2009
● after spring 2009
Base signal
Reference signal

8. Dryer efficiency (%)

9. Zero Air Measurements (Laboratory)

10. Important observations
Majority of TEOM-FDMS in NABEL showed poor comparability with gravimetry (too high values).
While reference signal seemed to be plausible, base signal were too high.
Poor performance seemed to be connected with low dryer efficiency.
With new dryers comparability was often better for a short period, but got worse rather quickly.
Filtered air gave not ± 0 μg/m3 signal (contribution from both reference and base signal).

13. Bern (good performance)
TEOM – Grav.
TEOM / Grav.
○ before spring 2009
● after spring 2009

14. Lausanne (good performance)
TEOM – Grav.
TEOM / Grav.
○ before spring 2009
● after spring 2009

15. Dübendorf (medium performance)
TEOM – Grav.
TEOM / Grav.
○ before spring 2009
● after spring 2009

16. Zürich (medium performance)
TEOM – Grav.
TEOM / Grav.
○ before spring 2009
● after spring 2009

17. AQUILA Recommendations
(AQUILA = Air Quality Reference Laboratories in Europe)
Recommendation 15 (November 2009)
For measurements of the AEI exposure measurements of PM2.5 the standard reference method shall be used where possible.
Recommendation 16 (November 2009)
AQUILA recommends to its members not to use new instruments for PM until the demonstration of equivalence is available.
Recommendation 17 (November 2009)
Current instrumentation may be used on the decision of the NRL/competent body and more rigorous QA/QC procedures shall be introduced as soon as possible.

18. Conclusions for EMEP
Also within EMEP, the gravimetric reference method shall be used where possible for measurements of PM.
In existing data base, correct documentation of metadata for PM (used method) is crucial.
When comparing PM data from different sites or analysing long term trends considerations concerning data homogeneity are very important.