The new UFP 330: Ten months of continuous measurements
B. Wehner
1
, A. Wiedensohler
1
, A. Zschoppe
2
, C. Peters
2
, A, Rudolph
2
, L. Hillemann
3
, M. Pitz
4,5
, J. Cyrys
4,5
,
J. Nowak
6
, C. Johansson
7
, H.-G. Horn
8
, R. Caldow
9
, G.J. Sem
9
, H. Gerwig
10
1
Leibniz-Institute for Tropospheric Research, 04318 Leipzig, Germany
2
Topas GmbH, 01279 Dresden, Germany
3
UBG – Staatliche Umweltbetriebsgesellschaft, 01445 Radebeul, Germany
4
Helmholtz Center München,German Research Center for Environmental Health, 85764 Neuherberg, Germany
5
Center for Science and Environment, University of Augsburg, 86159 Augsburg, Germany
6
CHMI – Czech Hydrometeorological Institute, 14306 Prague, Czech Republic
7
ITM – Department of Applied Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
8
TSI Gmbh, 52068 Aachen, Germany
9
TSI Inc., Shoreview, Minnesota, 55126, USA
10
LfUG - Saxon State Agency for Environment and Geology, Section Air Quality, Dresden, Germany
Keywords: number concentration, instrument development, network operation
Several epidemiological studies have shown a
relationship between high number concentrations of
ultrafine particles (< 100 nm) and adverse health effects.
However, most routine measurements of particulate
matter are limited to the mass concentration, e.g. PM10
or PM2.5. One major reason for this is that
commercially available measurement technique is
relatively expensive and needs more maintenance than
in the routine network operation can be provided. Within
the frame of the project UFIPOLNET a new instrument
to measure ultrafine particle number concentrations has
been developed which is easy to handle and needs less
maintenance than e.g. available SMPS systems.
The new instrument (Ultrafine Particle Monitor,
UFP330) consists of a Corona Charger, a DMA, and an
electrometer. The measured current is online transferred
to a number size distribution (20 – 800 nm) and locally
stored as number concentration within 6 size channels.
Within the frame of UFIPOLNET 4 prototypes of
the instrument have been built and are operated at 4
stations in Europe since February 2007: Dresden, Prag,
Augsburgs, and Stockholm. The first 10 months of data
have been used for a detailed analysis and conclusions.
The data availability for Prag, Augsburg, and Stockholm
was between 93.8% and 99.2% for the whole period.
The system in Dresden has been regularly checked in the
laboratory, therefore the availability is much lower there
and not comparable.
Data, stored in a common database, include not
only those from the UFP but also trace gases,
meteorological data, and DMPS, if available. The data
have been analysed for the first 10 months with regard
to diurnal, monthly and seasonal cycles, but also the
correlation with trace gases has been calculated. Here,
especially at traffic-dominated sites such as Prag, but
also Stockholm a good correlation between number
concentration < 100 nm and NO has been found.
Figure 1 shows exemplarily monthly averages for
number concentration in the range 20-30 nm (N1), 50-70
nm (N3), and 100-200 nm (N5). During most of the time
the site in Prag shows highest number concentration
followed by Stockholm during certain periods, while
Augsburg and Dresden show lowest concentrations.
These differences can be explained mainly by the
location within the selected city.
3 4 5 6 7 8 9101112
0
1
2
3
N1
Augsburg
Dresden
Prag
Stockholm
3 4 5 6 7 8 9101112
0
1
2
3
N3
Particle Concentration [*10
3
/cm³]
3 4 5 6 7 8 9101112
0
1
2
3
N5
Month
Figure 1: Monthly mean number concentrations in the size
ranges N1 (20-30 nm), N3 (50-70 nm), and N5 (100-200 nm)
at the 4 stations.
In January 2008 all 4 instruments were sent to
IfT laboratory and were compared among each other but
also against a TDMPS. Results showed significant
differences in the beginning, but a complete instrument
check and cleaning reduced the differences to < 10%.
Thus, this long term operation of the 4 prototypes had
the major conclusions:
instruments provide high data availability with
little maintenance
define maintenance intervals for the instrument
show needs for further improvements in the final
version.
This project (
www.ufipolnet.eu
) is financed by the LIFE financial
instrument of the European Community under No. LIFE04
ENV/D/000054.