Method of determining dielectric response of aerosol-generating article

An aerosol-generating device (10) includes a first terminal (42) and a second terminal (44) disposed in a heating chamber (18) such that the first terminal and the second terminal contact different portions of an aerosol-generating article (100). An alternating voltage is applied between the first and second terminals (42, 44) and a characteristic of a current flowing between the first and second terminals is measured. These characteristics are used to determine the dielectric response of the aerosol-generating article (100) at the applied frequency. The dielectric response includes both a conductive component and a capacitive component, and may be used to identify a state of the aerosol-generating article (100), such as whether the aerosol-generating article is properly inserted or an amount of a volatile substance, such as nicotine, which it contains. By comparing the dielectric responses before and after use of the device (10), the amount of volatile material that a user of the device (10) has inhaled can