A system for inhalation, comprising gas supply apparatus configured to separately supply at least NO, and a carrier gas mixture which contains O2； a mixer apparatus configured for receiving gases from the supply apparatus and mixing the NO with the carrier gas mixture to provide a therapeutic mixture； an inhaler device configured for receiving the therapeutic mixture and releasing the therapeutic mixture in an enclosed space of the inhaler device； a chemical sensing assembly configured for providing data pertaining to a concentration of at least NO2 in the inhaler device； and a controller configured for controlling flow of the therapeutic mixture responsively to the data.
