In the atmosphere of such harmful impurities as carbon monoxide, methane, ammonia, acetone, hydrogen sulfide, during the normal course of the flight, it changes very slowly, so monitoring them can not be carried out continuously, but discrete, with large time intervals (several weeks or even months). In cases where there is regular transport communication between the land and the manned device, control is carried out on the ground in the laboratory by chemical analysis of air samples delivered from the side of the apparatus in special ampoules. If there is no transport connection, then the number of impurities can be determined in the flight conditions.