An anesthetic vaporizer system includes a reservoir containing anesthetic agent, an agent level sensor measuring an agent level of the anesthetic agent in the reservoir, a display, and a controller. The controller is configured to receive agent level measurements from the agent level sensor over a time period, and determine the anesthetic agent is being added to the reservoir from an agent source based on the agent level measurements over the time period. A filling status is determined based on the agent level measurements and a filling status indicator is displayed based on the determined filling status.
