Aerosol generating system having means for handling consumption of a liquid subtrate
There is provided an electrically operated aerosol generating system for receiving an aerosol-forming substrate. The system includes a liquid storage portion for storing liquid aerosol-forming substrate, an electric heater including at least one heating element for heating the liquid aerosol-forming substrate, and electric circuitry configured to monitor activation of the electric heater and estimate an amount of liquid aerosol-forming substrate remaining in the liquid storage portion based on the monitored activation. There is also provided a method in an electrically operated aerosol generating system including a liquid storage portion for storing liquid aerosol-forming substrate and an electric heater including at least one heating element for heating the liquid aerosol-forming substrate, the method including monitoring activation of the electric heater and estimating an amount of liquid aerosol-forming substrate remaining in the liquid storage portion based on the monitored activation.
1. An electrically operated aerosol generating system configured to receive an aerosol-forming substrate, the system comprising:
a liquid storage portion configured to store a liquid aerosol-forming substrate;
an electric heater comprising at least one heating element configured to heat the liquid aerosol-forming substrate; and
electric circuitry configured to
monitor activation of the electric heater,
estimate an amount of the liquid aerosol-forming substrate remaining in the liquid storage portion based on the monitored activation, and
estimate a consumed amount of the liquid aerosol-forming substrate based on a first equation relating heating element temperature or resistance to liquid aerosol-forming substrate consumption up to a first threshold of temperature or resistance, and based on a second equation relating heating element temperature or resistance to liquid aerosol-forming substrate consumption above the first threshold.
2. The electrically operated aerosol generating system according to claim 1 , wherein the electric circuitry is further configured to estimate a consumed amount of the liquid aerosol-forming substrate, and to subtract the consumed amount from a known initial amount to provide an estimate of an amount of the liquid aerosol-forming substrate remaining in the liquid storage portion.
3. The electrically operated aerosol generating system according to claim 1 , wherein the electric circuitry is further configured to monitor activation of the electric heater by monitoring a temperature or a resistance of the at least one heating element over time.
4. The electrically operated aerosol generating system according to claim 1 , wherein the second equation is dependent on power applied to the at least one heating element.
5. The electrically operated aerosol generating system according to claim 1 , wherein the first equation is independent of power applied to the at least one heating element.
6. The electrically operated aerosol generating system according to claim 1 , wherein the first threshold is a boiling point of the liquid aerosol-forming substrate.
7. The electrically operated aerosol generating system according to claim 1 , wherein the first and second equations are stored in the electric circuitry.
8. The electrically operated aerosol generating system according to claim 7 , wherein a plurality of different first and second equations are stored in the electric circuitry for different compositions of liquid aerosol-forming substrate and for different power levels.
9. The electrically operated aerosol generating system according to claim 1 , wherein the electric circuitry is further configured to measure an electrical resistance of the at least one heating element, and to ascertain a temperature of the at least one heating element from a measured electrical resistance.
10. The electrically operated aerosol generating system according to claim 1 , further comprising a capillary wick configured to convey the liquid aerosol-forming substrate from the liquid storage portion to the electric heater.
11. A method, comprising:
providing an electrically operated aerosol generating system comprising a liquid storage portion configured to store a liquid aerosol-forming substrate and an electric heater comprising at least one heating element configured to heat the liquid aerosol-forming substrate;
monitoring, by electric circuitry, activation of the electric heater and estimating, by the electric circuitry, an amount of the liquid aerosol-forming substrate remaining in the liquid storage portion based on the monitored activation; and
estimating, by the electric circuitry, a consumed amount of the liquid aerosol-forming substrate based on a first equation relating heating element temperature or resistance to liquid aerosol-forming substrate consumption up to a first threshold of temperature or resistance, and based on a second equation relating heating element temperature or resistance to liquid aerosol-forming substrate consumption above the first threshold.