The general lifetime of the ‘amiNO’ sensors varies from one sensor to another.The amiNO-2000 is very durable and can be used for years.This sensor is supplied with extra membrane sleeves that can be changed by the user as needed.The amiNO-IV,amiNO-FLAT and amiNO-700 are constructed of very tough membranes that are not easily damaged.They can last for a year or longer.The main factor effecting the lifetime of all sensors depends mainly on the care used in handling and storing them.