Different types of gases may have different behaviors. But overall - for example, ambient air CO/CO2/PM2.5 (these are low density environments):

(1) Shelf life: 5 years in low density environment; Used in high-density environments for 2-3 years (many industrial processes produce certain types of gases, resulting in high density and shorter shelf life, requiring frequent recalibration).

(2) Warranty period: 1 year (we replace any defective units within the first year)