Characterization of aerosol generating materials

Abstract

Apparatus and methods for determining a property of an aerosol generating material of an aerosol generating device are disclosed. The aerosol generating device comprises a heater for heating the aerosol generating material in use. The apparatus is configured to monitor a first property of heating of the aerosol generating material, thereby determining a heating curve of the aerosol generating material; analyze the heating curve to identify features of the heating curve corresponding to heating of one or more components of the aerosol generating material; and determine the property of the aerosol generating material based on the identified one or more features.

Description

Technical Field

[0001] The present invention relates to determining characteristics of aerosol generating materials and more particularly to determining characteristics of aerosol generating materials of an aerosol generating device. Background Art

[0002] During use, smoking articles such as cigarettes, cigars, etc., burn tobacco to produce tobacco smoke. People have attempted to provide substitutes for these articles by producing products that release compounds without burning. The example of this product is the so-called "heat without burning" product or tobacco heating device or product, which releases compounds by heating without burning materials. The material can be, for example, tobacco or other non-tobacco products that may or may not contain nicotine. Summary of the invention

[0003] According to a first aspect of the present invention, there is provided a device for determining the characteristics of an aerosol generating material of an aerosol generating device, the aerosol generating device comprising a heater for heating the aerosol generating material during use; the device is configured to: monitor a first property of the heating of the aerosol generating material, thereby determining a heating curve of the aerosol generating material; and analyze the heating curve to identify heating curve characteristics corresponding to the heating of one or more components of the aerosol generating material; and determine the characteristics of the aerosol generating material based on the identified one or more characteristics.

[0004] Optionally, the apparatus is arranged to analyse the heating curve to identify features of the heating curve corresponding to vaporisation of one or more components of the aerosol generating material.

[0005] Optionally, the first property is related to the temperature of the aerosol generating material.

[0006] Optionally, the heater is an induction heater for inductively heating the aerosol generating material in use, and the apparatus is arranged to monitor a first property of the inductively heated aerosol generating material to thereby determine a heating curve of the aerosol generating material.

[0007] Optionally, the first property comprises a property of the induction heater.

[0008] Optionally, the first property comprises a temperature of a susceptor of the induction heater.

[0009] Optionally, the first property comprises an electrical property of the induction heater.

[0010] Optionally, the electrical property comprises a property indicative of a current provided to an inductor of the induction heater.

[0011] Optionally, the first property comprises a frequency characteristic of a resonant drive circuit of the induction heater.

[0012] Optionally, the frequency characteristic comprises a resonant frequency of the resonant drive circuit.

[0013] Optionally, the induction heating has a substantially constant induction heating power.

[0014] Optionally, the apparatus is arranged to: determine a rate of change of the first property; and identify one or more features of the heating curve based on the determined rate of change of the first property.

[0015] Optionally, the one or more characteristics comprise a portion of the heating curve wherein the first property remains substantially constant.

[0016] Optionally, the characteristic comprises the temperature of the aerosol generating material.

[0017] Optionally, the one or more characteristics include a second portion of the heating curve in which the first property varies, following a first portion of the heating curve in which the first property remains substantially constant.

[0018] Optionally, the characteristic comprises an endpoint of vaporization of one or more components of the aerosol generating material.

[0019] Optionally, the apparatus is arranged to control the heater based on the one or more determined characteristics.

[0020] Optionally, the apparatus is configured to: determine, based on the determined characteristic, that an endpoint of vaporisation of one or more components of the aerosol generating material has been reached; and control the heater in response to determining that an endpoint of vaporisation of one or more components of the aerosol generating material has been reached.

[0021] Optionally, the apparatus is configured to control the heater to further heat the aerosol generating material by a predetermined amount.

[0022] Optionally, the device is configured to control the supply of a predetermined amount of energy to the aerosol generating material.

[0023] Optionally, the apparatus is arranged to present information to a user based on the determined characteristic.

[0024] Optionally, the apparatus is arranged to present information to a user relating to one or more components of the aerosol generating material based on the determined characteristic.

[0025] Optionally, the apparatus is arranged to present to a user information relating to the environment in which the device is operated based on the determined characteristic.

[0026] Optionally, one of said one or more components of the aerosol generating material is a liquid.

[0027] According to a second aspect of the present invention, there is provided an aerosol generating device comprising: the apparatus according to the first aspect; and a heater.

[0028] Optionally, the heater is an induction heater comprising: one or the inductor; and one or the susceptor arranged to perform inductive energy transfer with the inductor, the susceptor being configured to heat the aerosol generating material contained in the aerosol generating device when in use.

[0029] Optionally, the aerosol generating device includes: an aerosol generating material.

[0030] Optionally, the mass of the heater is lower than the mass of the aerosol generating material.

[0031] According to a third aspect of the present invention, a method for determining the characteristics of an aerosol generating material of an aerosol generating device is provided, the aerosol generating device comprising a heater for heating the aerosol generating material when in use; the method comprising: monitoring a first property of the heating of the aerosol generating material, thereby determining a heating curve of the aerosol generating material; analyzing the heating curve to identify characteristics of the heating curve corresponding to the heating of one or more components of the aerosol generating material; and determining the characteristics of the aerosol generating material based on the identified one or more characteristics.

[0032] According to a fourth aspect of the present invention, there is provided a program which, when executed on a processor, causes the processor to perform the method of the third aspect.

[0033] Other features and advantages will become apparent from the following description, given by way of example only, and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 An aerosol generating device according to one embodiment is schematically illustrated.

[0035] Figure 2 An induction heater according to one embodiment is schematically illustrated.

[0036] Figure 3 illustrates a heating curve according to one embodiment;

[0037] Figure 4 a graph schematically illustrating a rate of change of an induction heating property according to one embodiment; and

[0038] Figure 5 A flow chart of a method according to an embodiment is schematically illustrated. DETAILED DESCRIPTION

[0039] Induction heating is the process of heating an electrically conductive object (or carrier) by electromagnetic induction. An induction heater may include an inductive element, such as an electromagnet, and a circuit for passing a varying current, such as an alternating current, through the electromagnet. The varying current in the electromagnet produces a varying magnetic field. The varying magnetic field penetrates a carrier appropriately positioned relative to the electromagnet, thereby generating eddy currents inside the carrier. The carrier has a resistance to the eddy currents, so the flow of the eddy currents relative to the resistance causes the carrier to be heated by Joule heating. In the case of whether the carrier comprises a ferromagnetic material such as iron, nickel or cobalt, hysteresis losses in the carrier, i.e., the orientation of the magnetic dipoles in the magnetic material changes due to its alignment with the varying magnetic field, can also generate heat.

[0040] In induction heating, heat is generated inside the carrier, allowing rapid heating, compared to heating by, for example, conduction. In addition, no physical contact is required between the induction heater and the carrier, allowing increased freedom of construction and application.

[0041] The induction heater may include an RLC circuit comprising a resistance (R) provided by a resistor, an inductance (L) provided in part by an inductive element (e.g., an electromagnet that may be configured to inductively heat a carrier), and a capacitance (C) provided by a capacitor, connected in series. In some cases, the resistance is provided by an ohmic resistance of the circuit portion connecting the inductor and the capacitor, and therefore the RLC circuit need not necessarily include such a resistor. Such a circuit may be referred to as, for example, an LC circuit. RLC and LC circuits may exhibit electrical resonance that occurs at a particular resonant frequency when the imaginary parts of the impedance or admittances of the circuit elements cancel each other. Resonance occurs in an RLC or LC circuit because the collapsing magnetic field of the inductor generates current in its windings, thereby charging the capacitor, while the current provided by the discharge capacitor simultaneously establishes a magnetic field in the inductor. In these circuits, when the circuit is driven at the resonant frequency, the series impedance of the inductor and the capacitor is minimized, and the circuit current is maximized. Therefore, driving the RLC or LC circuit at or near the resonant frequency can provide effective and / or efficient induction heating.

[0042] Figure 1An aerosol generating device 100 according to one embodiment is schematically illustrated. The aerosol generating device 100 is handheld. The aerosol generating device 100 includes a battery portion 106, an aerosol generating portion 104 and a mouthpiece portion 102. The aerosol generating portion 104 includes a controller 112, an induction heater 114 and an aerosol generating material 116. The aerosol generating material 116 can be removable and / or replaceable in the aerosol generating device 100, for example, via a cartridge (not shown) that is removably connected to the aerosol generating device 100. The battery portion 106 includes a battery 110. The battery 110 is configured to power the induction heater 114. The induction heater 114 is configured to inductively heat the aerosol generating material 116 during use. The controller 112 is configured to control the induction heating provided by the induction heater 114. The aerosol generating device 100 is arranged to heat an aerosol generating material 116 to generate an aerosol for inhalation by a user via the mouth portion 102 .

[0043] Aerosol generating material 116 can include materials that provide volatile components that are usually in the form of steam or aerosol when heated.Aerosol generating material 116 can be a material containing non-tobacco or a material containing tobacco.Aerosol generating material can, for example, include one or more of tobacco itself, tobacco derivatives, expanded tobacco (expanded tobacco), reconstructed tobacco, tobacco extract, homogenized tobacco or tobacco substitutes.The aerosol generating material can be in the form of ground tobacco, cut tobacco (cut rag tobacco), extruded tobacco, reconstructed tobacco, reconstructed material, liquid, gel, gelled sheet, powder or agglomerate.Aerosol generating material can also include other non-tobacco products, and according to the product, it may or may not include nicotine.The aerosol generating material can include one or more humectants, such as glycerol or propylene glycol.In certain embodiments, aerosol generating material 116 can include two or more components that are different from each other.For example, aerosol generating material 116 can have a first component containing a first phase and a second component with a second phase. For example, the aerosol generating material 116 may include (at ambient temperature and pressure) a component in solid form and a component in liquid form. For example, the aerosol generating material 116 may include a tobacco-containing material, which contains, for example, tobacco in solid form and one or more components in liquid form, such as water and / or a humectant, etc. The operating temperature of the aerosol generating device (i.e., the temperature at which the aerosol generating material 116 is heated to generate an aerosol when in use) may be higher than the vaporization or boiling temperature of one of the one or more components of the aerosol generating material 116, for example, higher than the vaporization or boiling temperature of the liquid component of the aerosol generating material 116, for example, higher than the boiling temperature of water. The liquid content of the aerosol generating material 116, for example, the water content, may vary depending on the batch, use and / or type of the aerosol generating material 116, and / or may depend on the external environment in which the aerosol generating material 116 is located.

[0044] In use, a user may activate the controller 112, for example, by means of a button (not shown) or a puff detector (not shown) known per se, to cause the induction heater 114 to heat the aerosol generating material 116, which causes the aerosol generating material 116 to generate an aerosol. The aerosol is generated in air drawn into the device 100 from an air inlet (not shown), from which it is carried to the mouth portion 102, where the aerosol leaves the device 100.

[0045] The induction heater 114 and / or the device 100 as a whole can be configured to heat the aerosol generating material 116 to a certain temperature range so as to vaporize at least one component of the aerosol generating material without burning the aerosol generating material. For example, the temperature range can be about 50-about 350°C, such as about 50-about 250°C, or about 50-about 150°C. In some embodiments, the temperature range is about 170-about 220°C. In some embodiments, the temperature range may not be this range, and the upper limit of the temperature range may be greater than 350°C.

[0046] Reference now Figure 2 , illustrates an induction heater 114 that can be used in an aerosol generating device 100 according to one embodiment. The induction heater 114 includes an RLC resonant circuit 200 for inductively heating a carrier 210. The resonant circuit 200 includes a resistor 204, a capacitor 206, and an inductor 208 connected in series. The resonant circuit 200 has a resistance R, an inductance L, and a capacitance C. The inductor 208 is configured to transfer inductive energy to the carrier 210. The carrier 210 is configured to heat the aerosol generating material 116. In some embodiments, the carrier 210 can be equipped with an aerosol generating material 116, and the carrier 210 and the aerosol generating material 116 can be provided in a cartridge (not shown) that is detachably connected to the entire device 100, for example, to allow replacement of the cartridge (not shown).

[0047] The inductance L of the circuit 200 is provided by an inductor 208 configured to inductively heat the carrier 210. The inductive heating of the carrier 210 is via the alternating magnetic field generated by the inductor 208, which induces Joule heating or hysteresis losses in the carrier 210 as described above. A portion of the inductance L of the circuit 200 may be due to the magnetic permeability of the carrier 210. The alternating magnetic field generated by the inductor 208 is generated by an alternating current flowing through the inductor 208. The alternating current flowing through the inductor 208 is the alternating current flowing through the RLC resonant circuit 200. The inductor 208, for example, may be in the form of a coil of wire.

[0048] The capacitance C of the circuit 200 is provided by the capacitor 206. The resistance R of the circuit 200 may be provided by the resistor 204, the resistance of the wires connecting the components of the resonant circuit 200, the resistance of the inductor 208, and / or the resistance of the current flowing in the resonant circuit 200 provided by the carrier 210 configured for inductive energy transfer with the inductor 108. It should be understood that the circuit 200 need not necessarily include the resistor 204, and the resistance R in the circuit 200 may be provided by the resistance of the connecting wires, the inductor 208, and / or the carrier 210.

[0049] The alternating current is driven in the circuit 200 by a suitable drive circuit 202, such as an H-bridge driver 202, or another variable or alternating current source. The drive circuit 202 can be controlled by the controller 112 to provide the alternating current in the resonant circuit 200. The drive circuit 202 is connected to a DC voltage source from the battery 110. For example, the drive circuit 202 can provide the alternating current in the circuit 100 from the DC voltage source of the battery 110 by reversing (and subsequently restoring) the voltage across the circuit via a switching assembly (not shown). This can be useful because it allows the RLC resonant circuit to be powered by a DC battery and allows the frequency of the alternating current to be controlled.

[0050] The drive circuit 202 is connected to the controller 112. The controller 112 controls the drive circuit 202 or its components (not shown) to provide an AC current I in the RLC resonant circuit 200 at a given drive frequency f. For example, the drive frequency f can be controlled to the resonant frequency f of the specific RLC circuit 200. r at or near .

[0051] It is desirable to determine a property of the aerosol generating material 116, for example, a property of the aerosol generating material 116 during inductive heating of the aerosol generating material 116. For example, it may be useful to determine or calibrate the determination of the temperature of the aerosol generating material 116, for example, to allow precise control of the heating of the aerosol generating material 116. As another example, it may be useful to determine when water or other components of the aerosol generating material 116 have been vaporized during heating, or to determine when a vaporization endpoint of a component of the aerosol generating material 116 has been reached, as this may allow improved control of further heating of the aerosol generating material up to the vaporization temperature of one or more other components. For example, the aerosol generating material 116 may include different water contents, which may vary widely depending on many factors such as the manufacturing process, the external environment, etc. Determining when substantially all of the water has been vaporized from the aerosol generating material 116 during heating may, for example, allow control of further heating of the aerosol generating material independent of the initial water content, and thus allow for more consistent aerosol delivery, as well as more efficient heating control. For example, once water has completely vaporized it can be inferred that a certain amount of additional energy will then be required to reach the vaporization temperatures of the other components.

[0052] According to an embodiment of the present invention, an apparatus (e.g., a controller 112) is configured to determine a characteristic of the aerosol generating material 116 during heating of the aerosol generating material 116. In summary, and as described in more detail below, the controller 112 is configured to monitor a first property P of inductive heating of the aerosol generating material 116, thereby determining a heating curve of the aerosol generating material 116. The controller 112 is configured to analyze the heating curve to identify features of the heating curve corresponding to heating (e.g., vaporization) of one or more components of the aerosol generating material 116. The controller 112 is configured to determine the characteristic of the aerosol generating material based on the identified one or more features. For example, the characteristic may be the temperature of the aerosol generating material 116, and / or a vaporization endpoint of a component (e.g., water) of the aerosol generating material 116. As explained in more detail below, determining such a characteristic may allow, for example, to accurately determine the temperature of the aerosol generating material, and / or to improve control of further heating of the aerosol generating material 116.

[0053] As described above, the controller 112 is arranged to monitor the first property P of the inductive heating of the aerosol generating material 116 , thereby determining a heating profile of the aerosol generating material 116 .

[0054] Reference now Figure 3 , schematically illustrates an exemplary heating curve 302 of the aerosol generating material 116. The heating curve 302 corresponds to a value of an inductively heated first property P of the aerosol generating material 116 as a function of time t. As the inductive heater 114 heats the aerosol generating material 116, the inductively heated first property P changes as a function of time t. The first property P may be recorded by the controller 112 as a function of time t continuously or discretely in, for example, a memory or a storage device (not shown).

[0055] In some embodiments, the first property P can be associated with the temperature of the aerosol generating material 116. For example, the property P can be the measured temperature of the aerosol generating material 116. For example, the temperature of the aerosol generating material 116 can be sensed by a separate temperature sensor (not shown) located at or near the aerosol generating material 116. The controller 112 can be communicatively coupled to the temperature sensor (not shown) and can collect temperature data from the temperature sensor (not shown) to monitor the temperature of the aerosol generating material 116 as a function of time t.

[0056] In some embodiments, the first property P is a property of the induction heater 114. For example, the first property P may include a temperature of a carrier 210 of the induction heater 114. For example, a temperature sensor (not shown) may be placed at or near the carrier 210. In this regard, it should be understood that the temperature of the carrier 210 may be a function of the heating of the aerosol generating material 116. The controller 112 may be communicatively coupled to the temperature sensor (not shown) and may collect temperature data from the temperature sensor (not shown) in order to monitor the temperature of the carrier 210 as a function of time t. Since the carrier 210 is configured to heat the aerosol generating material 116, for example, it may be in thermal contact or close thermal contact with the aerosol generating material 116, the determined carrier temperature may be the same or similar to the temperature of the aerosol generating material 116, or at least a portion of the aerosol generating material 116.

[0057] The first property P need not necessarily be a direct temperature measurement of the carrier 210 and / or the aerosol generating material 116 by a separate temperature sensor (not shown). For example, in some embodiments, the first property P comprises an electrical property of the induction heater 114 (or more generally the circuit 200), which may indicate the temperature of the carrier 210 and / or the aerosol generating material 116.

[0058] In one embodiment, the first property P includes a property indicative of the current I provided to the inductor 208 of the induction heater 114. As described above, the battery 110 can provide a DC voltage (and substantially a DC current) to the drive circuit 202, which then provides an alternating current to the resonant circuit 200 including the inductor 208. As the temperature of the carrier 210 increases through inductive heating, the property of the carrier 210 (e.g., the ohmic resistance of the carrier 210) may change. Purely by way of example only, the ohmic resistance of the carrier 210 may increase with temperature. The increase in the ohmic resistance of the carrier 210 may, in turn, increase the total effective resistance R of the resonant circuit 200. Therefore, according to Ohm's law, for a given DC supply voltage, such as provided by the battery 110, as the effective resistance R of the resonant circuit 200 increases, the current I drawn from the battery 110 by the drive circuit 202 will decrease, the current I flowing in the resonant circuit 200 will decrease, and thus the current I provided to the inductor 208 will decrease. Therefore, the current I provided to the inductor 208 of the induction heater 114 can be correlated to the relative temperature of the carrier 210 and can be used as a first property P of the inductive heating of the aerosol generating material 116 .

[0059] The current I drawn from the battery 110 by the drive circuit 202 and / or the current I flowing in the resonant circuit 200 and / or the current I provided to the inductor can be monitored by the controller 112 in a variety of ways. For example, the current I can be measured passively or actively. For example, an ammeter (not shown) can be applied to a power supply line (not shown) between the battery 110 and the drive circuit 202 to measure the current drawn by the drive circuit 202. The measurement result can be provided to the controller 112, which can monitor the current I as a function of time t as a first property P. As another example, a pick-up coil (not shown) can be placed near the inductor 208, and a voltmeter (not shown) can be used to measure the voltage across the pick-up coil (not shown) induced by the inductor 208. The induced voltage can be proportional to the current I flowing in the resonant circuit 200 and provided to the inductor 208. Therefore, the induced voltage is an example of a property indicating the current I provided to the inductor 208 of the induction heater 114. The measured induced voltage may be provided to the controller 112 , which may monitor the induced voltage and / or convert the induced voltage into a measure of the current I flowing in the resonant circuit 200 as a first property P.

[0060] It should be understood that in other embodiments, an electrical property of the circuit 200 other than the current I may be measured as the first property P.

[0061] In some embodiments, the first property P comprises a frequency characteristic of the resonant circuit 200 of the induction heater 114 .

[0062] For example, the frequency characteristic may include the resonant frequency f of the resonant driving circuit 200. r The resonant frequency f of the circuit 200 is r may depend on the capacitance C and the inductance L of the circuit 200 and may be given by:

[0063]

[0064] The inductance L of the inductor 208 and the inductance L of the resonant circuit 200 thereby depends on the magnetic permeability μ of the carrier 210. The magnetic permeability μ is a measure of the ability of a material to support a magnetic field formed within itself and represents the degree of magnetization that a material acquires in response to an applied magnetic field. The greater the magnetic permeability μ of the carrier 210, the greater the inductance L. The magnetic permeability μ of the material constituting the carrier 116 may vary with temperature. For example, for a carrier comprising ferromagnetic and ferrimagnetic materials operating below their Curie temperature Tc, as the temperature of the carrier 210 increases, the magnetic permeability μ of the carrier 210 will decrease, and thus the inductance L in the resonant circuit 200 will decrease, and therefore, via equation (1), the resonant frequency f of the resonant circuit 200 rTherefore, the resonant frequency f of the resonant circuit 200 of the induction heater 114 is r A first property P can be related to the relative temperature of the carrier 210 and can be used as an inductive heating property of the aerosol generating material 116 .

[0065] The resonant frequency f of the resonant circuit 200 r The measurement can be performed using any suitable method. r Under this condition, the series impedance Z of the inductor 208 and the capacitor 206 is minimum, so the circuit current I is maximum. The resonant frequency f of the circuit 200 is r The determination may be made by a controller 112 arranged to measure the frequency response of the resonant circuit 200. For example, the controller 112 may be arranged to intermittently measure the current I flowing in the RLC circuit 100 (or, as described above, a parameter associated with the current I flowing in the RLC circuit 200) as a function of a drive frequency f driving the RLC circuit. For example, the controller 112 may be arranged to control the drive circuit 202 to scan a range of drive frequencies f. During the sweep of the drive frequency, the current I flowing in the circuit 200 (or a parameter associated therewith) may be measured, and thus the frequency response of the RLC circuit 200 as a function of the drive frequency f may be determined. The resonant frequency f may then, for example, be determined from the frequency response. r It is determined as the frequency f at which the current I flowing in the circuit 200 is maximum. This process can be repeated over time to obtain the variation of the frequency f as a function of the time t (as a first property P).

[0066] Refer again Figure 3 , a first property P of the inductive heating of the aerosol generating material is monitored as a function of time t, thereby determining a heating curve 302 of the aerosol generating material 116. For ease of explanation, Figure 3 The following description assumes that the first property P is directly proportional to the temperature of the aerosol generating material, but it should be understood that, as described above, in other embodiments, any first property P of the inductive heating of the aerosol generating material may be used. In addition, for ease of explanation, Figure 3 The following description assumes that the power of the induction heating (i.e., the rate at which energy is provided to the aerosol generating material by induction heating) remains substantially constant along the heating curve 302, although it will be appreciated that, as described in more detail below, this need not necessarily be the case and that in other embodiments (not shown) the induction heating power may vary.

[0067] exist Figure 3In the illustrated embodiment, at time t0, the first property P is at some initial value P0, corresponding to some initial temperature of the aerosol generating material 116. As induction heating begins (in this embodiment, a constant heating power is employed), the first property P increases as a function of the time t between t0-t1. This corresponds to an increase in the temperature of the aerosol generating material 116, because the energy applied to the aerosol generating material 116 by the carrier 210 increases the temperature of the aerosol generating material 116. However, at time t1, the first property P substantially stops increasing (which may include increasing at a different rate / substantially decreasing rate), but instead remains substantially constant at the P1 value between times t2-t3. In other words, there is a portion 304 of the heating curve between t1-t2, in which the first property P remains substantially constant (steady) as a function of time t.

[0068] The first property P remains constant between times t1-t2 due to the latent heat of vaporization of the components of the aerosol generating material. The latent heat is the energy provided to the components of the aerosol generating material 116 at its boiling point to change its phase (e.g., from liquid to gas) without changing its temperature. In other words, the first property P remains substantially constant because, although the aerosol generating material 116 is still inductively heated (still heated at a constant heating power in this embodiment), the energy provided to the aerosol generating material is not used to increase the temperature of the aerosol generating material 116, but is used to vaporize the components of the aerosol generating material 116. As an example, the component may be water, whose boiling point is known to be 100°C. Therefore, it can be accurately determined that, between times t1-t2 when the first property remains substantially at P1, the temperature of the aerosol generating material 116 is 100°C, i.e., the value P1 of the first property P corresponds to a temperature of 100°C of the aerosol generating material 116.

[0069] At time t2, the first property P begins to increase again, which corresponds to an increase in the temperature of the aerosol generating material 116. The first property P increases at time t2 because all or substantially all of the components of the aerosol generating material 116 have vaporized, so the inductive heating of the aerosol generating material 116 again causes the temperature of the aerosol generating material 116 to increase. The portion 306 of the heating curve 302 where the first property P begins to increase again, immediately following the portion 304 where the first property P remains substantially constant, can correspond, for example, to a vaporization endpoint of a component of the aerosol generating material. For example, the component can be water, and it can be precisely determined that all or substantially all of the water of the aerosol generating material 116 has vaporized at t2, and, for example, the water content of the aerosol generating material at time t2 is substantially zero.

[0070] As described above, the device (e.g., controller 112) is configured to analyze the heating curve 302 to identify features of the heating curve 302 corresponding to vaporization of one or more components of the aerosol generating material 116. The device (e.g., controller 112) is configured to determine the characteristics of the aerosol generating material 116 based on the identified one or more features. For example, the controller 112 may include a processor (not shown) and a memory (not shown). The processor may, for example, extract the heating curve data stored in the memory and process the data to perform an analysis of the heating curve and / or determine the characteristics. It should be understood that the heating curve data includes at least two data points representing the first property P at two different times, which can then be used to calculate a change in the first property P.

[0071] In some embodiments, the feature of the heating curve 302 includes a portion 304 of the heating curve 302 in which the first property P remains substantially constant. The controller 112 can determine the temperature of the aerosol generating material based on identifying the feature that the first property P remains substantially constant. For example, as described above, the component can be water, which has a boiling point known to be 100° C., so when identifying the feature that the first property P remains substantially constant, the controller 112 can determine that the temperature of the aerosol generating material 116 is approximately 100° C.

[0072] In some embodiments, the mass of the heater 114, for example, the mass of the carrier 210 of the inductive heater 114, can be greater than the mass of the aerosol generating material 116. This can help ensure that the first property P is accurately correlated to the temperature of the aerosol generating material. For example, this can help ensure that features where the first property P remains substantially constant can be easily identified, which can help improve the reliability and / or accuracy of determining features of the heating curve and thereby determining the characteristics of the aerosol generating material 116. In addition, the power of the inductive heating provided can be such that the feature of the heating curve can be easily identified. For example, where the feature is a portion 304 where the first property P remains substantially constant, the power of the inductive heating provided can be such that the time between time t1-t2 is large enough to allow the portion 304 to be easily identified. As will be appreciated, the inductive heating power that allows the feature of the heating curve to be easily identified can depend on the mass and / or type of aerosol generating material used and / or the mass and / or type of carrier used to heat the aerosol generating material.

[0073] The aerosol generating material 116 may include other known vaporizable components. For example, it may be known that the aerosol generating material 116 includes multiple, for example, two, known vaporizable components. For example, it may be known that the first component has a boiling point of X°C and the second component has a boiling point of Y°C, where X°C is lower than Y°C. Therefore, when heating the aerosol generating material, the controller 112 can determine, for example, that the temperature of the aerosol generating material is X°C when a first portion (not shown) of the heating curve in which the first property P remains substantially constant is reached, and that the temperature of the aerosol generating material is Y°C when a second portion (not shown) of the heating curve in which the first property P remains substantially constant is reached. Therefore, the controller 112 can reliably and accurately determine the temperature of the aerosol generating material 116. Compared to, for example, direct temperature measurement using a temperature sensor, this can provide a more reliable temperature determination because this method may, for example, be less prone to calibration errors.

[0074] As another example, the one or more features may include a second portion 306 of the heating curve 302 in which the first property P changes, immediately following a first portion 304 of the heating curve 302 in which the first property P remains substantially constant. The controller 112 may determine a vaporization endpoint of one or more components of the aerosol generating material 116 based on the identification of such a feature. For example, as described above, the component may be water, and it may be accurately determined that when the first property begins to increase again immediately following the portion in which the first property P remains substantially constant, the vaporization endpoint of the water has been reached, i.e., all or substantially all of the water in the aerosol generating material 116 has been vaporized. Thus, it may be determined, for example, that the water content of the aerosol generating material 112 at this time is substantially zero. As described in more detail below, this may allow for improved control of further heating of the aerosol generating material 116.

[0075] In some embodiments, the controller 112 may be configured to control the induction heater 114 based on the one or more determined characteristics. For example, the controller 112 may control the induction heater 114 to increase or decrease the induction heating power, and / or apply different heating powers, and / or control the induction heater 114 to stop providing induction heating, and / or control the induction heater 114 to provide induction heating according to a predetermined control mode or sequence, and / or provide a predetermined further induction heating and / or a further predetermined amount of energy to the aerosol generating material 116. The controller 112 may control the induction heater 114, for example, by controlling the current provided to the drive device 202, or by controlling the drive frequency f of the drive circuit 202.

[0076] As described above, the determined characteristic may be the temperature of the aerosol generating material 116. The controller 112 may control the induction heater 114 based on the determined temperature of the aerosol generating material. For example, once it is determined that a given temperature (e.g., corresponding to the boiling point of a known component) has been reached, the controller 112 may control the induction heater 114 according to a predefined control sequence or a specific heating curve. This may help prevent overheating of the aerosol generating material, for example.

[0077] As another example, as described above, the determined characteristic may be a vaporization endpoint of a component of the aerosol generating material. The controller 112 may be configured to determine that a vaporization endpoint of one or more components of the aerosol generating material has been reached, and in response to the determination that a vaporization endpoint of one or more components of the aerosol generating material has been reached, control the induction heater. For example, the controller 112 may control the induction heater 114 to further inductively heat the aerosol generating material 116 by a predetermined amount. For example, the controller 112 may control the supply of a predetermined amount of energy to the aerosol generating material 116.

[0078] For example, different aerosol generating materials 116 that can be used with the aerosol generating device 100, or different batches of the same aerosol generating material 116 that can be used with the aerosol generating device 100 (e.g., used successively), can include different water contents (or different other component contents). Determining the point in time when all water (or other components) have been vaporized from the aerosol generating material 116 during heating allows further heating of the aerosol generating material to be controlled independently of the initial water (or other component) content, thereby allowing for more consistent aerosol delivery and more efficient heating control. In other words, the variation caused by water is eliminated (or significantly reduced), and therefore the controller 112 can supply a set amount of power to the carrier 210 / aerosol generating material 116 from the time when the water is substantially vaporized. This means that the operating temperature can be reached more accurately.

[0079] For example, after the water (or other component) is vaporized, the additional energy required to raise the temperature of the aerosol generating material 116 to a given operating temperature (e.g., to reach the optimal temperature at which the aerosol generating material 116 generates an aerosol) can be predetermined, and the controller 112 can control the induction heater 114 to provide the predetermined amount of energy to the aerosol generating material 116. This can allow simpler and / or more precise control of the induction heating. For example, the control can be independent of the initial component (e.g., water) content of the aerosol generating material, which may vary between uses, batches or types of the aerosol generating material, etc. For example, this can allow at least a portion of the induction heating control to be applied more accurately than a control that does not take these variations into account, and / or can be simpler than a control that takes these variations into account over the entire control range, for example. Therefore, the controller 112 can allow for improved control of the induction heating of the aerosol generating material, and can allow for improvements to the aerosol generating device 100.

[0080] In another embodiment, the controller 112 may be configured to display information to the user based on the determined characteristics of the aerosol generating material 116. For example, in the case where the determined characteristics indicate that all water (or other components) have been vaporized from the aerosol generating material 116, information indicating this may be provided to the user. In another embodiment, the information displayed to the user may indicate the temperature of the aerosol generating material 116. For example, when the determined characteristics indicate that all water has been vaporized from the aerosol generating material 116, the information may inform the user that the aerosol generating material 116 is at the boiling temperature of water. In other embodiments, information related to the components of the aerosol generating material 116 may be displayed to the user. For example, information related to the composition of the aerosol generating material 116 may be determined based on an analysis of the heating curve 302. For example, the analysis of the heating curve may reveal the presence of first and second vaporizable components having different boiling points in the aerosol generating material 116, as described above. Therefore, information indicating that these components are present in the aerosol generating material 116 may be displayed to the user. In some embodiments, the controller 112 may further determine whether the aerosol generating material 116 is a material approved for use with the device 100 based on the determined information regarding the composition of the aerosol generating material 116. In embodiments, the controller 112 may present such information to a user and / or the controller 112 may be configured to take action based on whether the aerosol generating material 116 is approved for use with the device 100, such as determining whether to allow the device 100 to operate while heating the aerosol generating material 116. In another embodiment, the controller 112 may be configured to determine a parameter related to the environment in which the device 100 is operating based on the determined characteristics of the aerosol generating material 116. For example, the controller 112 may determine the amount of water in the aerosol generating material 116 based on the characteristics of the heating curve 302. In embodiments, the amount of water in the aerosol generating material 116 may be indicative of the humidity of the environment in which the device 100 is operating. Thus, for example, information related to the humidity of the environment may be presented to the user.

[0081] In some embodiments, the controller 112 is configured to determine a rate of change of the first property P, for example, the rate of change of the first property as a function of time. The controller 112 may be configured to identify one or more features of the heating curve based on the determined rate of change of the first property. Figure 4 Schematically illustrates a graph 402 of the rate of change dP / dt of a first property P as a function of time t. Figure 3 Same, in Figure 4It is assumed in FIG. 4 that the induction heating has a constant heating power and that the property P is directly proportional to the temperature of the aerosol generating material 116. At time t0, the induction heating starts and the value of the rate of change dP / dt (i.e., in this embodiment, the first derivative of the first property P with respect to time t) is Q1. This remains the case until time t1, when the rate of change dP / dt decreases to essentially zero, where it remains until t2. This shows that in the portion 404 of the graph 402 in the time range t1-t2, the property P as a function of time t does not substantially change, i.e., remains essentially constant. As described above, for example, it can be determined from this that a component (e.g., water) has reached its boiling (or vaporization) point, and therefore the temperature of the aerosol generating material 116 at this point is the boiling (or vaporization) point of the component, e.g., 100°C for water. At time t2, in the second portion 406 of the graph 402, the rate of change dP / dt increases again. This indicates that the property P has begun to increase again (following the portion 404 in which the property P remains substantially constant), and thus the controller 112 can determine as described above that the vaporization endpoint of this component (e.g., water) of the aerosol generating material 116 has been reached. The controller 112 can perform control of the induction heater 114 as described above based on this determination. Identifying one or more features of the heating curve based on the determined rate of change of the first property P can allow the controller 112 to sensitively identify relevant changes in the first property P, and thus perform reliable and accurate control.

[0082] Figure 5 A method for determining a characteristic of an aerosol generating material 116 of an aerosol generating device 100 is schematically illustrated. As described above, the aerosol generating device 100 includes an induction heater 114 for inductively heating the aerosol generating material 116 in use. The method may, for example, be implemented by a device, such as a controller 112 of the aerosol generating device 100. The controller 112 (or other device) may include a processor (not shown) and a memory (not shown). The memory (not shown) may have instructions (e.g., a computer program) stored thereon, which, when executed by a processor (not shown), causes the controller 112 (or other device) to implement the method.

[0083] In step 502, the method includes monitoring a first property P of the inductively heated aerosol generating material 116 to determine a heating curve of the aerosol generating material 116. In some embodiments, the first property P may be any of the first properties P described above. The heating curve may, for example, be similar to the above reference Figure 3 as described.

[0084] In step 504, the method includes analyzing the heating curve to identify a feature of the heating curve corresponding to vaporization of one or more components of the aerosol generating material. As described above, the feature can include a portion in which the first property P remains substantially constant (e.g., indicating vaporization of a component), and / or a portion in which the first property P changes followed by a portion in which the first property P remains substantially constant (e.g., indicating an endpoint of vaporization of a component).

[0085] In step 506, the method includes determining a characteristic of the aerosol generating material based on the identified one or more characteristics. As described above, the characteristic may be, for example, the temperature of the aerosol generating material 116 and / or the vaporization endpoint of a component of the aerosol generating material 116. Figure 5 Not shown, but the method may include, for example, as described above, controlling the induction heating based on the determined characteristic.

[0086] In some embodiments, monitoring of the inductively heated first property P, thereby determining a heating curve, and analyzing the heating curve to identify features corresponding to vaporization of one or more components of the aerosol generating material 116, can occur substantially continuously or can occur substantially simultaneously (i.e., simultaneously). For example, analysis of the heating curve can be performed as the first property is monitored, i.e., in real time. For example, analysis can be performed for a current value of the first property and one or more values ​​of the first property P that were determined or recorded immediately prior to the current value of the first property P. Performing the monitoring and analysis substantially simultaneously can allow for responsive determination of characteristics of the aerosol generating material 116 and can allow for responsive, and therefore more accurate and reliable, control of the aerosol generating device 100.

[0087] In some of the above embodiments, it is assumed that the first property P is directly proportional to the temperature of the aerosol generating material. However, it will be appreciated that this is not necessarily the case, and in other embodiments, the first property P may have other dependencies on the temperature of the aerosol generating material, but nonetheless the heating curve may be analyzed to determine characteristics of the heating curve corresponding to vaporization of one or more components of the aerosol generating material.

[0088] In some of the above embodiments, it is assumed that the induction heating is performed at a constant induction heating power. However, it should be understood that the aerosol generating material 116 does not necessarily need to be heated at a constant induction heating power to determine the characteristics, and in other embodiments, a variable induction heating power may be used. Similarly, it should be understood that the first property P does not necessarily need to be monitored as a direct function of time t to determine the heating curve, that is, it should be understood that the determined heating curve is not necessarily the first property P as a direct function of time t. For example, in other embodiments, the first property P may be monitored as a function of the energy E supplied to the aerosol generating material 116 and / or consumed by the induction heater 114, for example. Thus, the heating curve may include the first property P as a function of the energy E supplied to the aerosol generating material 116 and / or the energy consumed by the induction heater 114. The energy E may be determined, for example, by multiplying the electrical power supplied to the induction heater 114 (i.e., consumed by the induction heater 114) (which may, for example, be the same or similar or proportional to the induction heating power supplied by the induction heater 104) by the time t over which the power is supplied. Similar to the situation with respect to the above embodiments, when the components of the aerosol generating material 116 begin to vaporize, the first property P can remain substantially constant as a function of the energy E provided, because the energy E is not used to increase the temperature of the aerosol generating material, but is used to vaporize the components of the aerosol generating material. Thus, for example, at this point, the temperature of the aerosol generating material 116 can be accurately determined as the boiling point (or vaporization point) of the component. Similarly, when the first property P increases immediately after the portion in which the first property remains substantially constant, it can be determined that the vaporization endpoint of the component has been reached. As described above, control of further heating by the induction heater 114 can then be controlled based on the point having been reached.

[0089] In some of the above embodiments, it is described that the means for determining the characteristics of the aerosol generating material 116 is the controller 112 of the aerosol generating device 100. However, it should be understood that this is not necessarily the case, and in other embodiments, the means may not be an internal or integral component of the aerosol generating device 100, and may, for example, be provided as a separate device.

[0090] In another embodiment, the characteristics of the first property P can be used to identify the aerosol generating material 116 and / or determine whether the aerosol generating material 116 is intended for use with the aerosol generating device 100. For example, the controller can determine that the aerosol generating material 116 is not to be used with the aerosol generating device 100. This can be based on identifying the aerosol generating material explicitly (e.g., by name or composition), or by comparing the characteristics of the first property P with (e.g., pre-stored) expected characteristics. If the measured characteristics of the first property P are different from the expected characteristics, the controller can prevent heating of the aerosol generating material 116, or can provide a warning to the user of the device 100.

[0091] In some of the above embodiments, it is described that the aerosol generating device includes an induction heater for inductively heating an aerosol generating material during use, and the device is described as being configured to monitor a first property of the inductive heating of the aerosol generating material to determine a heating curve of the aerosol generating material. However, it should be understood that this is not necessarily the case, and in some embodiments, the aerosol generating device may include any heater for heating the aerosol generating material during use, and the device may be configured to monitor the first property of heating the aerosol generating material to determine the heating curve of the aerosol generating material. For example, in some embodiments, the heater may be a resistive heater and the first property may be, for example, the temperature of the aerosol generating material measured by a temperature sensor, for example, as described above.

[0092] In some of the above-described embodiments, it is described that the device analyzes the heating curve to identify features of the heating curve corresponding to the vaporization of one or more components of the aerosol generating material. However, it should be understood that this is not necessarily the case, and in some embodiments, the device may analyze the heating curve to identify features of the heating curve corresponding to (more generally) heating of one or more components of the aerosol generating material. For example, in addition to the vaporization of one or more components of the aerosol generating material, the heating curve may be characterized by, for example, a certain heating gradient (e.g., the heating temperature rise rate of one or more components of the aerosol generating material). The identified heating gradient can then be used, for example, to determine the characteristics of the aerosol generating material. For example, different components of the aerosol generating material may have different heat capacities, which may affect the identified heating gradient. Therefore, the characteristics of the aerosol generating material may be the nature (property, identity, feature, identity) of the components of the aerosol generating material and / or, for example, the type of aerosol generating material. As another embodiment, different amounts of a certain aerosol generating material (or its components) may result in different observed heating gradients. Thus, a property of the aerosol generating material may be the (current) amount of the aerosol generating material (or its components). It will be appreciated that other features of the heating curve corresponding to heating of one or more components of the aerosol generating material may be identified and may be used to determine the property of the aerosol generating material.

[0093] In another embodiment, the device can analyze the heating curve using gradients associated with different parts of the heating curve to identify features of the heating curve corresponding to the vaporization of one or more components of the aerosol generating material. For example, before a component such as water is vaporized from the aerosol generating material, the heating curve can have a first gradient M1. However, after all the water in the aerosol generating material has been vaporized, the heating curve can have a second gradient M2. In this embodiment, the second gradient M2 will be greater than the first gradient M1 because at this point in the heating curve with gradient M2, the aerosol generating material 116 requires less energy to raise its temperature by a given amount because there is no longer water to heat. The point tangent to the heating curve with gradients M1 and M2 can be determined, thereby determining the inflection point in the heating curve. It is thereby possible to determine features of the heating curve corresponding to the vaporization of one or more components of the aerosol generating material. This can be useful if the inflection point cannot be easily identified by other techniques, for example, if the induction heating power is so high that the inflection point is short-lived.

[0094] It should be noted that it is the features of the heating curve of the aerosol generating material itself that are identified to determine the characteristics of the aerosol generating material. Therefore, although in some embodiments, the properties of the (induction) heater can be monitored to determine the heating curve of the aerosol generating material, it is still necessary to identify the features of the heating curve corresponding to the heating of one or more components of the aerosol generating material in order to determine the characteristics of the aerosol generating material. For example, this may be contrary to certain features of the heater (e.g., the carrier of the induction heater) itself. Identifying features of the heating curve corresponding to the heating of one or more components of the aerosol generating material in order to determine the characteristics of the aerosol generating material can allow the determination of characteristics that are specific to the heated aerosol generating material, which has the benefits, for example, as described above, such as improved consistency and improved heating control.

[0095] The above embodiments should be understood as illustrative embodiments of the present invention. It should be understood that any feature described with respect to any one embodiment may be used alone or in combination with other features described, and may also be used in combination with one or more features of any other embodiment, or any combination of any other of the other embodiments. In addition, equivalents and modifications not described above may also be adopted without departing from the scope of the present invention as defined by the appended claims.

Claims

1. An apparatus for determining a property of an aerosol generating material of an aerosol generating device, the aerosol generating device comprising a heater for heating the aerosol generating material in use; the apparatus being arranged to: monitoring a first property of the heating of the aerosol generating material to thereby determine a heating curve of the aerosol generating material; analyzing the heating curve to identify features of the heating curve corresponding to heating of one or more components of the aerosol generating material; and determining a property of the aerosol generating material based on the identified one or more of the features, wherein the characteristic comprises a portion of the heating curve wherein the first property remains substantially constant; wherein the first property is related to the temperature of the aerosol generating material; and Wherein the characteristic comprises the temperature of the aerosol generating material.

2. An apparatus according to claim 1, wherein the apparatus is configured to analyse the heating curve to identify features of the heating curve corresponding to vaporisation of one or more components of the aerosol generating material.

3. A device according to claim 1 or 2, wherein the heater is an induction heater for inductively heating the aerosol generating material during use, and the device is configured to monitor a first property of the inductive heating of the aerosol generating material so as to determine a heating curve of the aerosol generating material.

4. The apparatus of claim 3, wherein the first property comprises a property of the induction heater.

5. The apparatus of claim 4, wherein the first property comprises a temperature of a carrier of the induction heater.

6. The apparatus of claim 4, wherein the first property comprises an electrical property of the induction heater.

7. The apparatus of claim 6, wherein the electrical property comprises a property indicative of a current provided to an inductor of the induction heater.

8. The apparatus of claim 4, wherein the first property comprises a frequency characteristic of a resonant drive circuit of the induction heater.

9. The apparatus of claim 8, wherein the frequency characteristic comprises a resonant frequency of the resonant drive circuit.

10. The apparatus of claim 3, wherein the induction heating has a substantially constant induction heating power.

11. The device according to claim 1 or 2, wherein the device is configured to: determining a rate of change of said first property; and Based on the determined rate of change of the first property, one or more of the features of the heating curve are identified.

12. The apparatus of claim 1 or 2, wherein one or more of the features comprises a second portion of the heating curve in which the first property changes immediately following a portion or a first portion of the heating curve in which the first property remains substantially constant.

13. The device of claim 12, wherein the characteristic comprises an endpoint of vaporization of one or more components of the aerosol generating material.

14. The device according to claim 1 or 2, wherein the device is configured to: The heater is controlled based on the one or more determined characteristics.

15. The device according to claim 14, wherein the device is configured to: determining that an endpoint of vaporization of one or more components of the aerosol generating material has been reached based on the determined characteristic; and The heater is controlled in response to a determination that an endpoint of vaporization of one or more components of the aerosol generating material has been reached.

16. The device according to claim 15, wherein the device is configured to: The heater is controlled to further heat the aerosol generating material by a predetermined amount.

17. The device according to claim 16, wherein the device is configured to: A predetermined amount of energy is controlled to be provided to the aerosol generating material.

18. The device according to claim 1 or 2, wherein the device is configured to: Display information to users based on identified characteristics.

19. The device according to claim 18, wherein the device is configured to: Information related to one or more components of the aerosol generating material is presented to a user based on the determined characteristics.

20. The device according to claim 17, wherein the device is configured to: Information related to the environment in which the device is operating is presented to the user based on the determined characteristics.

21. The device according to claim 18, wherein the device is configured to: Information related to the environment in which the device is operating is presented to the user based on the determined characteristics.

22. The device of claim 1 or 2, wherein one of the one or more components of the aerosol generating material is a liquid.

23. An aerosol generating device comprising: The device according to any one of claims 1 to 22; and Heater.

24. An aerosol generating device according to claim 23, wherein the heater is an induction heater, and the induction heater comprises: a sensor or said sensor; and A carrier or the carrier is arranged for inductive energy transfer with the inductor, the carrier being arranged, in use, to heat aerosol generating material contained in the aerosol generating device.

25. An aerosol generating device according to claim 23 or 24, comprising: The aerosol generating material.

26. An aerosol generating device according to claim 25, wherein the mass of the heater is lower than the mass of the aerosol generating material.

27. A method for determining a property of an aerosol generating material of an aerosol generating device, the aerosol generating device comprising a heater for heating the aerosol generating material in use, the method comprising the steps of: monitoring a first property of the heating of the aerosol generating material to thereby determine a heating curve of the aerosol generating material; analyzing the heating curve to identify features of the heating curve corresponding to heating of one or more components of the aerosol generating material; and determining a property of the aerosol generating material based on the identified one or more of the features, wherein the characteristic comprises a portion of the heating curve wherein the first property remains substantially constant; wherein the first property is related to the temperature of the aerosol generating material; and Wherein the characteristic comprises the temperature of the aerosol generating material.

28. A computer program product comprising a computer program, characterized in that When the computer program is executed on a processor, the computer program causes the processor to perform the steps of the method according to claim 27.

29. An apparatus for determining a property of an aerosol generating material of an aerosol generating device, the aerosol generating device comprising a heater for heating the aerosol generating material in use; the apparatus being arranged to: monitoring a first property of the heating of the aerosol generating material to thereby determine a heating curve of the aerosol generating material; analyzing the heating curve to identify features of the heating curve corresponding to heating of one or more components of the aerosol generating material; and determining a property of the aerosol generating material based on the identified one or more of the features, wherein the characteristic comprises a second portion of the heating curve in which the first property changes immediately following a first portion of the heating curve in which the first property remains substantially constant; wherein the first property is related to the temperature of the aerosol generating material; and Wherein the characteristic comprises the endpoint of vaporization of one or more components of the aerosol generating material.

30. An aerosol generating device comprising The apparatus of claim 29; and Heater.

31. A method for determining a property of an aerosol generating material of an aerosol generating device, the aerosol generating device comprising a heater for heating the aerosol generating material in use; the method comprising the steps of: monitoring a first property of the heating of the aerosol generating material to thereby determine a heating curve of the aerosol generating material; analyzing the heating curve to identify features of the heating curve corresponding to heating of one or more components of the aerosol generating material; and determining a property of the aerosol generating material based on the identified one or more of the features, wherein the characteristic comprises a second portion of the heating curve in which the first property changes immediately following a first portion of the heating curve in which the first property remains substantially constant; wherein the first property is related to the temperature of the aerosol generating material; and Wherein the characteristic comprises the endpoint of vaporization of one or more components of the aerosol generating material.

32. A computer program product comprising a computer program, characterized in that When the computer program is executed on a processor, the computer program causes the processor to perform the steps of the method according to claim 31 .

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