On Friday, June 12, 2026, a workshop on the operation and maintenance of the CPC 3750 (Condensation Particle Counter) instrument was held at the Institute of Geophysics, Faculty of Physics, University of Warsaw. The workshop was led by specialists from TSI Incorporated and attended by representatives of the University of Warsaw and Warsaw University of Technology. The workshop was organized to enhance cooperation between the two universities in accordance with the construction of a new component of the ACTRIS infrastructure – Aerosol In-Situ (AIS) – at the Warsaw ACTRIS National Facility, led by Dr hab Iwona Stachlewska, prof. ucz.

The workshop, lasting from 9:00 to 12:00, was divided into theoretical and practical sections. In the first part, participants learned about the device's operating principles, best practices, and recommendations for periodic maintenance. The most important aspects of the instrument's operation were discussed, and an instructional video presenting the various stages of technical inspections was presented.

During the practical part, led by Dr. Jianqiang Zhu from TSI Incorporated, participants performed the instrument maintenance procedure step by step following the manufacturer's recommendations. Test measurements were then conducted, and the device's operation was verified.

The meeting concluded with a discussion, which provided an opportunity to exchange experiences related to the use of equipment used in atmospheric aerosol research.

These initiatives not only enhance skills and expertise in operating modern research equipment but also promote collaboration among research centers and support the development of the ACTRIS infrastructure in Poland.

We thank all participants and presenters for their commitment, valuable guidance, and the opportunity to gain practical knowledge!

The workshop was attended by representatives of:

• University of Warsaw – Wojciech Kumala, Krzysztof Markowicz, Dominika Szczepanik, and Olga Zawadzka;
• Warsaw University of Technology – Anna Gayer, Katarzyna Maciejewska, and Magdalena Reizer;
• TSI Incorporated – Lucia Bustin and Jianqiang Zhu
• and NGLab (TSI's distributor in Poland) – Maciej Marlęga

Text: dr Dominika Szczepanik