Welcome to the
Center for Aerosol In-Situ - European Center for Aerosol Calibration and Characterization (CAIS-ECAC)
In the frame of the European Research Infrastructure ACTRIS-ERIC, the Center for Aerosol In-Situ - European Center for Aerosol Calibration and Characterization (CAIS-ECAC) is one of the Central Facilities for the ACTRIS National Facilities and external users worldwide. CAIS-ECAC’s mission is to offer operational support for quality assured and controlled physical and chemical aerosol in situ measurements & sampling, to conduct traceable instrument calibration, and to perform laboratory analysis of aerosol samples. Furthermore, CAIS-ECAC develops and offers Near-Real-Time tools for fast data submission and central quality control.
CAIS-ECAC is a consortium, consisting of seven facilities. The WCCAP (World Calibration Center for Aerosol Physics), PACC (Prague Aerosol Calibration Center), and CCC (Cluster Calibration Center) are responsible for aerosol microphysical and optical aerosol variables. The OCTAC-CC (Organic Tracer and Aerosol Constituents - Calibration Center), ERLAP (European Reference Laboratory for Air Pollution), the ACMCC (Aerosol Chemical Monitor Calibration Center) and EMC2 (Element Mass Calibration Center) are in charge of the chemical & elemental aerosol variables.
To visit the CF and the workshops, please click on the icon.
which consists of
Seven Central Facilities
and is responsible for 65 National Facilities in 18 countries in Europe.
Events & Announcement
Dear ACTRIS Community,
We are very happy to announce that the registration for the ACTRIS Science Conference 2026 is finally open! You can register for the conference here. This year we received a record number of submissions, and we are excited to see ACTRIS Science Conference grow and see you be a part of it.
- Early-bird registration deadline is February 17th 2026.
- Registration deadline for all presenters is March 17th 2026.
- Overall registration deadline is April 3rd 2026.
ACTRIS Science Conference 2026 will take place at Scandic Fornebu in Oslo, Norway from 20th to 23rd of April 2026, and we look forward to seeing many of you there!
Workshops at Central Facilities
Event:
Training Workshop for ACSM data submission
date:
May 6th-7th 2026
announcement:
ACMCC is pleased to announce a training workshop for ACSM data submission on EBAS, which will take place virtually on May 6th and 7th.The first day will be dedicated to Quad-ACSM; the second to ToF-ACSM.New versions of submission tools (especially for ToF) will be released by these dates.NF participation is highly encouraged. Fill in the file below to register and receive corresponding communicationsNote that there is an emerging initiative for long-term trend analysis on ACSM data, within the framework of the next IPCC AR7 report. As a joint activity with the NF Forum WG “Aerosol Mass Spectrometer”, there will be dedicated discussions on how to maximize data submission, as well as the interest of data resubmission.
Activity &
Newsletter
Meetings
Minutes
Aerosol In-Situ Commiunity Meetings
OGTAC-CC Commiunity Meetings
last update January 2024
last update September 2022Measurement
Guidelines
Labeling
Process
Labeling Process Step 1A - initial acceptance
The labeling process for a ACTRIS National Facility consists of several steps:
The sketch explains the procedure of the step 1a, the initial acceptance, at CAIS-ECAC.
- step 1a (initial acceptance)
- step 1b (performance evaluation after 2 consecutive years of operation)
- step 1c (review approval and obtaining the ACTRIS label)
- step 2 (regular re-evaluation)
Procedure Of The Labeling
Operational SupportOperational support which is organized by CAIS-ECAC on regular basis:
Operational Support | Instrument | Frequency | Modality of provision |
| Calibration Workshops at CAIS-ECAC | Microphysical & optical instruments | biannually | Call launched by CAIS-ECAC |
| Round-Robin-Tests at CAIS-ECAC | OC/EC Organic tracers Element analysis | annually | Call launched by CAIS-ECAC |
| NF audits | Not regular | Call launched by CAIS-ECAC |
Dear ACTRIS Aerosol In Situ Community,
For your information and consideration, the upcoming Summer School on Formation and Growth of Atmospheric Aerosols, which will be held in Hyytiälä, Finland, from 17–27 August 2026.
The summer school will bring together students and early-career researchers from across the field, offering lectures, hands-on activities, and opportunities to exchange ideas with leading experts. In addition to being scientifically stimulating, it will provide a great chance to build connections within the atmospheric science community.
Sincerely, Silja Häme
Dear all,
We´re pleased to invite you to the 2nd OGTAC-CC community meeting that will be held online on April 28 from 1 to 4 p.m. CEST.
This is the second virtual community meeting within the framework of ACTRIS for all interested in QA/QC of particulate organic tracers (OTs). We invite you to a lively workshop where OGTAC-CC is presenting its current implementation status, latest news and future activities of the calibration centre.
On the one hand, this invitation is addressed to those NFs that officially indicated their interest in OT measurements from filters. On the other hand, we would like to invite in particular potential future NFs to inform about the current status and next steps connected to OGTAC-CC. NFs that indicated for example offline OC/EC measurements from filters are highly welcome to join this community meeting and to discuss potential interests, opportunities of OT measurements and applications.
We would be very glad for everybody to participate who could imagine that the activities of OGTAC-CC might be of any assistance for future ACTRIS work.
If you are planning to participate, please send a brief notice to: mothes[at]tropos.de
Please find attached the agenda of the meeting including the online zoom link.
We´re looking forward to get in touch with you.
Please feel also free to distribute this invitation to everybody interested.
All the best,
Falk and Hartmut
Dear community,
you can find the actual version of the "MPSS evaluation software with R" as a download under "Measurement Guidelines" -> "Particle number size distribution - mobility diameter 10-800 nm". Please use only the approved version by WCCAP to avoid any problems or mistakes during the evaluation process.
First information about the software were given during the last community meeting on February 12th, 2026. Please have a look at the presentation in the section "Meetings & Minutes".
your WCCAP team
Event:
Invitation to Aerosol In-Situ Community Meeting WCCAP
Topic:
09:00-09:05 Welcome & Introduction
09:05-09:35 Harmonized procedure for data correction from nephelometers and filter based absorption photometers
09:35-10:05 Quality control for nephelometers – real user example
10:05-10:10 Announcement of the upcoming OGTAC-CC community meeting in April and the next hands-on training workshop in May 2026
10:10-11:00 Questions and Discussion
Date:
12 March 2026
Time:
9 - 11 a.m. CET
Info:
link is provided in the community
Location:
online meeting
The course will be held for 5 days from Monday 18th to Friday 22nd of May 2026 at TROPOS ACD in Leipzig. The number of participants is limited to 8. The course is free of charge. Participants have to cover only their travel and accommodation costs.
Topic:
Theory and practice – Offline chromatographic (LC-MS and GC-MS) determination of organic tracer compounds and organic and elemental carbon (OC/EC) measurements in particulate matter collected on filters.
Subscription via email to ogtac-cc[at]tropos.de (registration deadline May 1st)
For any questions don´t hesitate to contact Dr. Falk Mothes (mothes[at]tropos.de).
Event:
Invitation to the 2nd OGTAC-CC community meeting (online)
Topic:
Ongoing and planned activities of the calibration centre for particulate organics
Status of the technical requirements and measurement guidelines
Offline data workflow
Past, current and planned inter-laboratory comparisons
Status labelling
Date:
28 April, 2026
Time:
1-4 p.m. CEST
Info:
Registration via brief notice to mothes[at]tropos.de
Location:
online meeting
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