ИСТИНА

General introduction why low coster technology has to be developed. The most important are the aerosol calibration issues and the time stability at this type of atmospheric conditions. The calibration sift due to sensor state or sensor loading effect is reported against aerosol Scientific instruments. This type of outdoor measurements should be examine for functional details and general construction sensor. Crucial system components should be tested against cold weather and snow such as the housing robustness the electrical power stability, electronic connections, data transmission over the internet. Moscow is the most densely populated northernmost megacity in Europe. Sampling campaign was performed at the Aerosol Complex of Moscow State University (MSU), located at the Meteorological Observatory (MO) (southwest of Moscow) MO MSU is not directly affected by local pollution sources such as large transport roads or industrial facilities, thus this site is classified as an urban background classified as urban background site. Airsensor set was installed at 1.5 m above a roof of a container (Fig.1). A long term calibration and evaluation is ongoing for the outdoor version of the AirSensis low cost sensor system Intercalibration campaign was performed in the most cold season, from December 2022 to February 2023 when temperature was varied from +3o to -21oC. For the meteorological parameters the data was used from the MO Meteorological service. Simultaneously with the Airsensis, optical particle counter (OPS, TSI) and mobile real-time aerosol spectrometer Palas @ Frog were operated as well as ambient particulate PM10 monitor TEOM 1400a by Mosecomonitoring. Ambient T and RH sensors show well ( R2=0.95) correlation with Meteorological service data. Relatively good correlation for PM10 (R2=0.44) and PM2.5 (R2=0.069) is found