An inhalation device for inhaling a vaporized substance that includes metering capabilities to inform a user when a particular amount of substance has been consumed. The inhalation device can include a sensor that senses the vaporized substance and a processor that utilizes data from the sensor to meter the amount consumed. The inhalation device can also define a session, which is a time in which a user can consume a particular amount. During the session, a user can start and stop inhaling and resume inhaling. When the user stops inhaling the inhalation device will halt vapor production and will resume production when the user resumes inhaling.
