WP8: European Centre for Aerosol Calibration (ECAC)

WP8 Objectives

-    Quality-assurance of physical, optical, and chemical in-situ aerosol measurements
-    Capacity building to perform high-quality physical, optical, and chemical in-situ aerosol characterization

Provision of access to the following infrastructures

The infrastructure will provide 605+180+60 units of access (1 UoA = 1 RWD (research-working day) of 8 labour hours) over the duration of the project. Between 2 and 10 UAs are needed to inter-calibrate each instrument, depending on its complexity. The amount of instruments to be inter-calibrated or round-robin tests yearly is in average about 70-80.

Description of the infrastructure

Name of the infrastructure and its installations: European Centre for Aerosol Calibration.

which consists of 3 installations:
-    the World Calibration Centre for Aerosol Physics (WCCAP)
-    the European Laboratory for Air Pollution (ERLAP)
-    the Aerosol Chemical Speciation Monitor Calibration Centre (ACMCC)

Location (town, country) of the infrastructure:
-    WWCAP: Leipzig, Germany
-    ERLAP: Ispra, Italy
-    ACMCC: Gif / Yvette, France

These 3 installations address the instruments used to determine the main physical, optical, and chemical aerosol properties, which are not independent from each other. Monitoring the quality of these measurements is crucial since all these properties are used to determine the sources and environmental impacts of aerosols. A thorough assessment of data uncertainty will be provided by each of the 3 installations.

Web site address:
-    WCCAP:
-    ERLAP:
-    ACMCC:

Annual operating costs (excl. investment costs) of the infrastructure (€):
-    WCCAP: 283167 €
-    ERLAP: 17755 €
-    ACMCC: 86 453 €

Description of the infrastructure

The infrastructure ECAC consists of 3 installations, which have demonstrated their expertise in providing calibration and inter-laboratory comparison services to the scientific and air quality monitoring communities for several years. It addresses instruments that measure particle number concentration and size distribution, cloud condensation nucleus concentration and spectrum, particle light scattering and absorption coefficients, and main chemical constituents, i.e. organic and elemental carbon, the main inorganic volatile compounds such as ammonium, nitrate, sulfate, and organic fragments. ECAC has been particularly active in standardizing these measurements in the frame of the projects EUSAAR and ACTRIS for the past 8 years. The experience gained during these projects makes ECAC mature enough to provide inter-calibration service as TNA to a wide community including traditional ACTRIS partners and associates, new users like scientific communities dealing with e.g. air pollution and health, air quality monitoring networks, as well as SMEs manufacturing aerosol instruments. This service is indispensable to trace the quality of the in-situ aerosol data delivered by European stations to international open data banks (including data required by the Directive 2008/50/EC), which are further used for air pollution source and effect assessments. It also stimulates innovation from manufacturers to develop instruments delivering more precise, accurate, and traceable data. The whole infrastructure has become an essential part for data quality assurance of the European but also the worldwide aerosol scientific and network community with recognitions, especially in Asia, North- and South-America due to the WMO-GAW program.

1.    World Calibration Centre for Aerosol Physics (WCCAP)
The WCCAP was founded in 2002 to serve as a competence centre for in-situ physical and optical aerosol measurement as part of the world-wide GAW-program (Global Atmosphere Watch) of the WMO (World Meteorological Organization). This WCCAP is world-wide unique for the quality assurance of physical and optical in-situ aerosol measurements and station audits to improve infrastructures. It is presently used by partners and associate partners of the research infrastructure project ACTRIS (previously EUSAAR), by the European (often also partners and associate partners of ACTRIS) and international GAW-community, in regional EU-projects, and for GUAN (German Ultrafine Aerosol Network), whose members are also partly involved in ACTRIS as associate partners. The WCCAP is well established and recognized worldwide and coordinates activities with NOAA (National Oceanic and Atmospheric Administration). Nationally, the WCCAP is the aerosol competence centre for the German “Umweltbundesamt” and the Saxonian State Office. SMEs for particle technology participated frequently in the intercomparison activities.

2.    The European Reference Laboratory for Air Pollution (ERLAP)
ERLAP was founded in 1994 to serve as a calibration facility for measurements of particulate matter and gaseous air pollutants in Europe. Inter-laboratory comparison exercises have been organized yearly or more for 2 decades. As a service of the European Commission, ERLAP provides support independently of national or private interests, which makes it unique in Europe. In the field of OC and EC measurements, it has been mainly used by EUSAAR and ACTRIS partners and associates, members of EMEP (the program underpinning the UN convention on long-range trans-boundary air pollution), GAW global and regional stations, and European National Reference Laboratories (AQUILA) since 2006.

3.    The ACSM calibration centre (ACMCC)
This installation offers unique logistic facilities to compare up to 15 Aerosol Chemical Speciation Monitors (ACSM). It provides a large set of independent co-located on-line/off-line aerosol measurements for chemical, physical and optical parameters, which for some of them are calibrated at the WCCAP and used to validate ACSM data through chemical, mass and optical closure studies. This calibration centre is presently mainly used by ACTRIS partners and associates, and French Regional Air quality networks. During ACTRIS, ACMCC served as the calibration site for ACSMs from14 major European Stations.
Services currently offered by the infrastructure:

The service offered by the infrastructure includes:
-    Inter-comparisons and hands-on capacity building of operators for instrument operation and data processing at ECAC installations for Condensation Particle Counters, Aerosol Electrometers, Mobility, Aerodynamic and Optical Particle Size Spectrometers, Extinction monitors, Integrating Nephelometers, Absorption Photometers, Cloud Condensation Nuclei Counters (including reference instruments) at the WCCAP and Aerosol Chemical Speciation Monitors at the ACMCC
-    Inter-laboratory comparisons of OC and EC measurements based on synthetic standards and ambient test samples provided by the ERLAP facility (remote access).
-    On-site intercomparisons with reference instruments of physical and optical in-situ aerosol instruments, including station audits
-    Hands-on capacity building of fundamentals in aerosol physics, physical and optical aerosol in-situ instruments, and aerosol in-situ sampling
ECAC is able to serve 70-80 projects/users every year (usually one project is related to one user), depending on the instruments type. As a calibration infrastructure, ECAC produced recommendations and standards for various measurements widely applied across the world.

Description of work

Modality of access

The call for TNA to the different ECAC installations will be continuously open. The access to ECAC installations will be jointly coordinated by the project management team (PMT) and WP8 leader (TROPOS). The request for accessing the calibration infrastructure as a whole (independently of the installation) should be addressed online to the PMT in the form of a short proposal (template available), including the scientific objectives for the access, description of the instrument to be calibrated, as well as people in charge. Applications from groups fulfilling the ACTRIS standardization criteria will have a priority to be accepted by the evaluation panel.

TROPOS will manage and follow up on the proposals with the calibration installation leaders, with support by NA3 task leaders. The decisions to be taken with NA3 include:
1.    Recommendation for a minimum frequency of the instrument intercomparisons, calibrations for various instruments types, and round robin tests for partners in the consortium (a minimum frequency is required in order to be compliant with ACTRIS standards).
2.    Recommendation for stations to qualify for on-site intercomparisons with a reference instruments

The work is divided in three activities, 1) instrument intercomparison and calibration at the calibration installations, 2) round-robin intercomparisons based on test samples, and 3) on-site intercomparisons with reference instruments at the stations. The support offered has already been routinely provided to external users for about 1 decade for activities (1) and (2). Activity (3) was successfully performed within other WCCAP-related activities such as in in regional EU-projects “UFIREG” or “Ultraschwarz” as well as within GUAN.

Every year, centralized instrument inter-comparisons or calibrations will be offered by ECAC to the European and international community for the types of instruments listed below. The costs for WCCAP are based on a combination of unit and actual costs; actual costs are applied to expenses related to on-site intercomparisons with reference instruments at user stations (non fixed costs). ACMCC is based on unit costs. For the unit costs, one unit of access (UoA) is defined as 1 RWD (research-working day) which is equivalent to 8 labour hours of the installation staff. The access costs for ERLAP are calculated on the basis of actual costs since the costs of the installation operation cannot reliably be split between the activities and groups (outside the project) for the past two years.The number of units of access  needed for each instrument to be calibrated or intercompared at WCCAP or ACMCC are following:
-    Mobility, aerodynamic and optical particle size spectrometers (4 UoA per instr.)
-    Monitors for scattering and absorption coefficients (4 UoA per instr.)
-    Condensation particle counters (2 UoA per instr.)
-    Cloud condensation particle counters (5 UoA per instr.)
-    Organic and elemental carbon analyzer (3 UoA per instr.)
-    Aerosol chemical speciation monitor (10 UoA per instr.)

A limited number of on-site intercomparisons with reference instruments are offered for following instruments:
-    Mobility particle size spectrometers (10 UoA)
-    Condensation particle counters (3 UoA)

After the instrument intercomparison, calibration, or round robin test, the user will obtain a certificate about the performance of the instrument or the analysis.

Activity 1: Intercomparison and calibration workshops at calibration facilities (WCCAP and ACMCC)

The typical sequence for an instrument intercomparison and calibration workshop is as follows: (1) pre-workshop preparation of the laboratory including quality assurance of the reference instruments, (2) reception of the candidate instruments, (3) unpacking and technical check together with the operator and the manufacturer (Aerodyne Res. Inc.) for ACSM, (4) status intercomparison against the reference instrument, (5) fixing technical problems, (6) hands-on capacity building for state-of-the-art operation and calibration, (7) calibration of the candidate instrument, (8) daily briefings discussing the progress and status, (9) final intercomparison against the reference instrument, (10) packing of instrument together with the operator, (11) shipping of the candidate instrument, and (12) post workshop writing of the intercomparison and calibration report.

Activity 2: Round-robin intercomparison based on test samples (ERLAP)

The typical sequence for a round robin test for OC/EC analysis is as follows: (1) provision of test material (traceable calibration material, synthetic and/or ambient particulate matter filter samples), (2) assessment of the test material homogeneity, (3) distribution of test material aliquots to participants, (4) collection, tabulation, and evaluation of the round-robin test results according to ISO methods 5725-2 and 13528:2005(E), (5) report writing and publication, and (6) interaction with under-performing participants.

Activity 3: On-site intercomparisons with reference instruments (WCCAP)

The typical sequence for an on-site intercomparison is as follows: (1) quality assurance of the reference instruments before shipment, (2) shipping of the reference instrument to the station, (3) travel to the station, (4) unpacking and technical check of the reference instrument, (5) status intercomparison against the reference instrument, (6) fixing technical problems, (7) hand-on capacity building for state-of-the-art operation and calibration, (8) calibration of the candidate instrument, (9) station audit of the aerosol program, (10) final intercomparison against the reference instrument, (11) packing and shipping of the reference instrument, (12) post on-site writing of the intercomparison and calibration report.

Scientific, technical and logistical support

For ERLAP and ACMCC, shipping support can be offered to the external and international partners. Assistance for customs clearance is provided when needed. Instruments are stored in a safe and dry place at room temperature upon receipt. Within the available budget, selected applicants can be provided with support money for travel. During the intercomparison and calibration activities, users will be offered hand-on training. This training will be partly supported by Aerodyne Res. Inc. (MA, USA) for ACSM. Furthermore, additional training material, as well as access to internet and data evaluation software will be provided.

Outreach to new users

The promotion of the TNA activities will be made through the WCCAP, ERLAP, ACMCC, and ACTRIS websites to provide comprehensive information on upcoming instrument calibration workshops and access opportunities. The institutes in charge of the installations will also promote the access to ECAC through E-mailing lists of various networks beside ACTRIS in which they are involved (WMO-GAW, EMEP-TFMM, AQUILA, GUAN etc.). One major emphasize will be given to SMEs to obtain access to TNA intercomparison and calibration activities to 1) quality assure new commercial aerosol instrumentation as well as 2) to enhance the transfer of technology and standardizations between ACTRIS and the SMEs.

Review procedure under this proposal

Following verification of the applications by the PMT for formal compliance with EU regulations, they will then be followed-up on by TROPOS and forwarded for peer review to the TNA “in-situ aerosol” User Selection Panel. The User Selection Panel will be composed of the leader of NA3, the responsible TNA task leader and at least two independent international experts. Requests will be accepted at any time from any eligible group. The applications will be thoroughly evaluated against clearly defined selection criteria. The selection panel bases its selection on scientific merit. Beside user groups within the consortium, priority will be given to user groups, who did not use the installatiosn, previously, and especially who work in countries in which no equivalent research infrastructures exist. Applications will be treated due to the principles of transparency, fairness and impartiality.