Measurement equipment and process for aerosol generating device life cycle testing configuration

Abstract

A test fixture is provided for analyzing an aerosol generated by an aerosol generation system comprising an aerosol-forming substrate and a mouthpiece. The test fixture comprises an airflow channel extending from a first channel opening configured to receive a mouthpiece of the aerosol generation system. The test fixture further comprises a sensing assembly comprising an emitter configured to emit electromagnetic radiation into the airflow channel and a receiver configured to receive at least a portion of the electromagnetic radiation from the airflow channel. The test fixture further comprises a pump assembly configured to draw air in a first direction through the airflow channel such that in a first configuration of the test fixture, aerosol generated by the aerosol generation system, in use, is drawn from a mouthpiece received in the first channel opening and through the airflow channel, and a controller configured to determine at least one characteristic of the aerosol drawn through the airflow channel based on a signal received from the sensing assembly. Methods of analyzing an aerosol using the test fixture and methods of detecting defects in an aerosol generation system are also provided.

Description

[Technical field]

[0001] The present disclosure relates to a test fixture for analyzing an aerosol generated by an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece. The present disclosure also relates to a method for analyzing an aerosol generated by such an aerosol generating system using the test fixture, and to a method for detecting defects in such an aerosol generating system.

[0002] Aerosol generating systems are known that include an aerosol-forming substrate, such as a tobacco-containing substrate, and a mouthpiece. In such systems, heat is typically applied to the aerosol-forming substrate to generate an aerosol that can be inhaled by a user of the system by inhaling through the mouthpiece. Heat may be transferred to the aerosol-forming substrate from a heat source, such as a chemical, electrical, or combustible heat source. In such systems, the aerosol-forming substrate is not combusted itself.

[0003] Many aerosol-generating systems electrically heat the aerosol-forming substrate. Such an aerosol-generating system may comprise an aerosol-generating device comprising a power source and a heater assembly. The aerosol-forming substrate is contained in a separate aerosol-generating article, which typically takes the form of a rod and contains a plug of the aerosol-forming substrate at or towards its distal end. In use, the aerosol-generating article is received in the aerosol-generating device, and the heater assembly is used to heat the aerosol-forming substrate. Heating may result from resistive heating of a heater element of the aerosol-generating device, which is in thermal contact with the aerosol-forming substrate, or from inductive heating of a susceptor element of the aerosol-generating device or aerosol-generating article, which is in thermal contact with the aerosol-forming substrate.

[0004] Alternatively, the electrically heated aerosol generating system may comprise an aerosol generating device comprising a power source and a heater assembly, and the aerosol-forming substrate may be a liquid or gel contained in a reservoir. The reservoir is often formed by the housing of a separate cartridge that is receivable in the aerosol generating device. In use, the cartridge is received in the aerosol generating device, and the heater assembly is used to heat the aerosol-forming substrate. The heater assembly comprises a heater element that may be part of the cartridge.

[0005] Other aerosol-generating systems are not electrically heated. One such system consists of an aerosol-generating article in which an aerosol is generated by the transfer of heat from a combustible carbonaceous heat source to a physically separated aerosol-forming substrate containing tobacco material located downstream of the combustible carbonaceous heat source. In use, volatile compounds are released from the tobacco material by heat transfer from the combustible carbonaceous heat source to the aerosol-forming substrate and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user. Heat may be transferred from the combustible carbonaceous heat source to the aerosol-forming substrate by one or both of forced convection and conduction.

[0006] All the above aerosol generating systems comprise or consist of consumable components including an aerosol-forming substrate. It is necessary to be able to analyze the aerosol generated by the aerosol generating system during use. This may be for quality and warranty testing of the consumable. When a consumable is consumed in combination with an aerosol generating device, analysis of the aerosol may also be used for quality and warranty testing of the device. For example, the quantity or quality of the generated aerosol may be determined in the test.

[0007] It is known to use chromatography, e.g., high performance liquid chromatography (HPLC) columns, to analyze the aerosol generated by an aerosol generating system. However, chromatography equipment is expensive and complex. Furthermore, it is not possible to perform a puff-by-puff analysis of the generated aerosol in real time using chromatography. Puff-by-puff analysis advantageously allows for improved analysis of the generated aerosol, since it provides information about the performance of the aerosol generating system throughout the entire usage cycle or during the product life cycle. For example, certain characteristics of the generated aerosol may be expected to change throughout the usage cycle, such as decreasing or increasing during successive puffs. Puff-by-puff analysis may advantageously allow for detection of deviations from expected patterns.

[0008] It would be advantageous to provide low cost, simple testing equipment suitable for analyzing aerosols generated by aerosol generating systems, and it would also be advantageous to provide testing equipment capable of performing puff-by-puff analysis of the generated aerosols.

[0009] Both consumables, such as aerosol-generating articles, and aerosol-generating devices, are typically mass-produced. For quality assurance reasons, it is typically necessary to test a percentage of the articles or devices manufactured in a batch. This can cause problems such as production line downtime, and the need to store individual batches until testing can be performed. These problems are particularly acute in the production of aerosol-generating articles in the form of rods, which are typically manufactured using very high speed and continuous rod-forming techniques.

[0010] It would be advantageous to provide a test fixture that is particularly suitable for use in conjunction with a production line and that does not cause production line downtime or complicate the production process.

[0011] In a first aspect of the present disclosure, there is provided a test setup for analysing an aerosol generated by an aerosol-forming substrate. The test setup may be for analysing an aerosol generated by an aerosol-generating system comprising an aerosol-forming substrate and a mouthpiece.

[0012] The test fixture may include an airflow channel extending from a first channel opening configured to receive a mouthpiece of the aerosol generation system.

[0013] The test fixture may include a sensing assembly. The sensing assembly may include an emitter. The emitter may be configured to emit electromagnetic radiation. The emitter may be configured to emit the electromagnetic radiation into the airflow channel.

[0014] The sensing assembly may further comprise a receiver. The receiver may be configured to receive the electromagnetic radiation. The receiver may be configured to receive at least a portion of the electromagnetic radiation from the airflow channel. In particular, the receiver may be configured to receive at least a portion of the electromagnetic radiation from the airflow channel emitted by the emitter. Preferably, the receiver may be configured to measure an intensity of the received electromagnetic radiation.

[0015] The test fixture may include a pump assembly. In a first configuration of the test fixture, the pump assembly may be configured to draw air in a first direction through the airflow channel. The pump assembly may be configured to draw air in a first direction through the airflow channel, such that in use, an aerosol generation generated by the aerosol generation system is drawn from a mouthpiece received in the first channel opening and through the airflow channel. In this way, the pump assembly may advantageously mimic a user inhaling on a mouthpiece of the aerosol generation system in a manner that corresponds to real-world use of the system. Preferably, the pump assembly may draw air in the first direction through the airflow channel for a predetermined time and then stop drawing air in the first direction through the airflow channel. This may be referred to as a puff. The pump assembly may be configured to perform multiple successive puffs. The pump assembly may advantageously draw air in a reproducible manner through the airflow channel. In this way, reproducible results may be achieved for different aerosol generation systems or different puffs of the same aerosol generation system.

[0016] The pump assembly may also be configured to vary the characteristics of the air drawn through the airflow channel between different puffs, for example to accommodate particular usage patterns of the aerosol generation system or according to particular test conditions.

[0017] The test fixture may include a controller. The controller may be configured to determine at least one characteristic of the aerosol drawn through the airflow channel. The controller may be configured to determine at least one characteristic of the aerosol drawn through the airflow channel based on a signal received from the sensing assembly.

[0018] For example, the controller may be configured to determine at least one characteristic of the aerosol drawn through the airflow channel based on the signal received from the receiver. Electromagnetic radiation emitted by the emitter may pass through the aerosol drawn through the airflow channel. At least a portion of the electromagnetic radiation may interact with the aerosol. For example, the electromagnetic radiation may be absorbed by the aerosol. The amount of absorption may depend on the amount of aerosol present in the flow channel. The amount of absorption may depend on other characteristics of the aerosol, for example, the chemical composition of the aerosol. Using this relationship, the controller may be advantageously configured to determine at least one characteristic of the aerosol. Advantageously, the determined characteristic may be used to identify whether the aerosol generation system is faulty or operating correctly.

[0019] The amount of electromagnetic radiation transmitted through an aerosol may be related to the amount of electromagnetic radiation absorbed by the aerosol: the more radiation absorbed by the aerosol, the less radiation is transmitted through the aerosol.

[0020] One advantage of such a test fixture is that it is relatively inexpensive and straightforward to use, especially when compared to chromatography equipment used in conventional methods to analyze aerosols. Furthermore, data may be collected using the test fixture in near real-time. This may be advantageously because measurements from the sensing assembly may be continuously updated as the aerosol is drawn through the airflow channel. Similarly, advantageously, puff-by-puff analysis of the generated aerosol may be possible using the test fixture.

[0021] The above-mentioned test facility is particularly advantageous in the context of a production line for producing aerosol generating systems, or components of aerosol generating systems, such as aerosol generating devices, or preferably consumables comprising an aerosol-forming substrate. Near real-time data generation may ensure that quality assurance tests performed using the test facility are fast. A defective aerosol generating system or component of an aerosol generating system may be determined quickly, without the need for quality assurance tests to be performed separately from the manufacturing process. For example, quality assurance tests may require one or more components in a batch of components to be tested. The components to be tested may be removed from the production line. The components may be tested for defects using test facilities, which may advantageously be located adjacent to the production line. Meanwhile, the remainder of the batch may continue through the production line, possibly being packaged. If defects are detected, the respective batch may be identified and removed from the production line. If no defects are detected, the respective batch may continue, for example to be shipped. Advantageously, it may not be necessary to stop the production line to allow for quality and assurance tests. There is no need to transport the components being tested to a dedicated testing laboratory to perform gas chromatography-mass spectrometry, to perform sample preparation, or to store batches while quality and assurance testing is performed.

[0022] Preferably, the test facility may be for analysing an aerosol generated by an electrically heated aerosol generating system for electrically heating an aerosol-forming substrate. For example, the electrically heated aerosol generating system may comprise an aerosol generating device for receiving a consumable comprising the aerosol-forming substrate. The consumable may be an aerosol-generating article in the form of a rod that is receivable within the device.

[0023] Alternatively, the consumable may be a cartridge comprising a housing defining a reservoir for containing the aerosol-forming substrate. The cartridge may be receivable within a corresponding aerosol generating device.

[0024] Either the consumable or the device may include a mouthpiece receivable by the first channel opening of the test fixture.

[0025] If the consumable is an aerosol-generating article, a distal end of the aerosol-generating article received within the device may protrude from the device. The distal end of the article may form a mouthpiece receivable by the first channel opening of the test fixture.

[0026] If the consumable is a cartridge, the housing of the cartridge may define a mouthpiece that is receivable by the first channel opening of the test fixture. Alternatively, the housing of the device may form a mouthpiece that is receivable by the first channel opening of the test fixture.

[0027] Additionally or alternatively, the test fixture may be for analyzing aerosols generated by an aerosol-generating system comprising a heated aerosol-generating article including a combustible heat source, such as a carbonaceous combustible heat source, an aerosol-forming substrate downstream of the combustible heat source, and a mouthpiece downstream of the heat source, the mouthpiece being receivable by a first channel opening of the test fixture.

[0028] As used herein, a "defect" may be any problem with the aerosol-generation system that may be identified based on a characteristic of the aerosol that can be detected using the sensing assembly, which may include a defect, if present, in at least one of the aerosol-forming substrate or the aerosol-generation device.

[0029] In one embodiment, the test facility may be configured to identify defects in the aerosol-forming substrate. The defects may relate to the physical or chemical properties of the aerosol-forming substrate. The aerosol-forming substrate may include an aerosol former, such as glycerin or propylene glycol. An example of a defect relating to the chemical properties of the aerosol-forming substrate may include an incorrect concentration or amount of aerosol former, which may result in an unexpected amount of aerosol being generated. For example, if the amount of aerosol former is too low, less aerosol may be generated, which may increase the amount of electromagnetic radiation received at the receiver.

[0030] Alternatively or additionally, the aerosol-generating system may comprise an aerosol-generating device for heating the aerosol-forming substrate, and the test facility may be configured to identify defects in the aerosol-generating device. This may include a device that heats the aerosol-forming substrate to an incorrect temperature. If the device underheats the aerosol-forming substrate, less aerosol may be generated. If the device overheats the aerosol-forming substrate, more aerosol may be generated. Such defects may be identified based on measurements made by the receiver, since the amount of electromagnetic radiation received at the receiver may depend on the amount of aerosol generated.

[0031] The sensing assembly may be positioned between the first channel opening and the pump assembly. In this manner, the pump assembly may be configured to draw air through the airflow channel and past any sensors of the sensing assembly. This may advantageously ensure that the sensing assembly is able to measure properties of the aerosol drawn through the airflow channel. For example, at least a portion of the electromagnetic radiation emitted by the emitter may pass through the aerosol drawn through the airflow channel and then be received by the receiver.

[0032] The controller may be configured to compare at least one determined characteristic to one or more predetermined values ​​for the or each determined characteristic, or one or more predetermined ranges of values ​​for the or each determined characteristic. For example, the controller may be configured to compare the determined first characteristic to a first predetermined value or a first predetermined range of values. Additionally or alternatively, the controller may be configured to compare the determined second characteristic to a second predetermined value or a second predetermined range of values. Additionally or alternatively, the controller may be configured to compare the determined third characteristic to a third predetermined value or a third predetermined range of values.

[0033] One or more predetermined values ​​or one or more ranges of predetermined values ​​may correspond to values ​​for each determined characteristic that are acceptable. In particular, one or more predetermined values ​​or one or more ranges of predetermined values ​​may correspond to values ​​for each determined characteristic that are indicative of the aerosol generation operating correctly.

[0034] The controller may be configured to determine that the aerosol generation system is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within a range of predetermined values ​​for that characteristic.

[0035] Determining a faulty system based on a comparison of the determined characteristic to a predefined value may advantageously mean that the controller does not need to perform a detailed analysis of the generated aerosol in order to determine a faulty system. For example, the first characteristic may be the transmittance of the aerosol as measured using the sensing assembly. The generated aerosol of a properly operating aerosol generating system may have a transmittance that corresponds to a predefined value or range of values. Thus, the controller may advantageously determine a faulty system if the transmittance does not equal the predefined value or fall within the range of values. The transmittance of the aerosol may depend at least on the amount of aerosol generated and the chemical composition of the aerosol generated, but advantageously the controller does not need to determine the actual amount or chemical composition of the generated aerosol in order to determine a faulty device.

[0036] The one or more predetermined values ​​or the one or more ranges of predetermined values ​​may advantageously be values ​​determined by previous experimentation in which a threshold value for an expected value between a properly operating aerosol generating system and a defective aerosol generating system has been determined.

[0037] One or more predetermined values ​​or one or more ranges of predetermined values ​​may be stored in the memory of the controller. These predetermined values ​​may be entered into the memory, for example, during manufacture of the test fixture. Alternatively, the predetermined values ​​may be entered into the memory of the controller prior to performing an analytical operation using the test fixture. For example, a user may enter the values ​​into a user interface of the test fixture, or the values ​​may be uploaded from a separate database. Alternatively, the values ​​may be determined by determining one or more characteristics of each of the aerosols of an aerosol generation system that is known to operate correctly in a separate routine. The values ​​for the characteristics may be used as the predetermined values.

[0038] As used herein, references to a "predetermined value" are intended to include a "range of predetermined values" unless expressly stated otherwise. For example, the statement above that a predetermined value is entered into the memory of the controller also encompasses a range of predetermined values ​​that are entered into the memory of the controller.

[0039] The test facility may comprise a user interface. If the aerosol generation system is found to be defective, the test facility may be configured to indicate this using the user interface. If the aerosol generation system is found to be defective, the test may be configured to indicate this using the user interface. The user interface may comprise a display for indicating whether the aerosol generation system is defective or not defective.

[0040] The testing facility may preferably be suitable for analysing aerosols generated by two or more types of aerosol generating system(s) equipped with different aerosol-forming substrates.

[0041] The first channel opening may comprise a mouthpiece receiving portion. The mouthpiece receiving portion may be shaped to receive a mouthpiece of the aerosol generation system within the opening of the mouthpiece receiving portion. The mouthpiece receiving portion may be shaped to provide a seal between the test fixture and the mouthpiece of the aerosol generation system.

[0042] As used herein, the term "seal" means that the interface between the mouthpiece receiving portion of the test apparatus and the received mouthpiece of the aerosol generation system is sufficiently airtight to prevent substantial leakage of air through the interface. This may advantageously ensure that when the pump assembly draws air through the airflow channel in a first direction, air is drawn through the aerosol generation system and into the airflow channel (thus bypassing the aerosol generation system) rather than through the interface.

[0043] The mouthpiece receiving portion may be removable. The mouthpiece receiving portion may be replaceable. Thus, if the test fixture is configured for use with a different type of aerosol generation system, the mouthpiece receiving portion may be replaced with a mouthpiece receiving portion that is specifically configured for the particular aerosol generation system being tested.

[0044] Aerosols generated by different types of aerosol-generating systems or different aerosol-forming substrates may differ, and so the one or more predetermined values ​​or the range of one or more predetermined values ​​may also differ. The controller memory may advantageously store values ​​for a number of different types of aerosol-generating systems or aerosol-forming substrates. Alternatively, or additionally, appropriate values ​​may be entered into the controller memory prior to carrying out the analytical operation using a test fixture as described above.

[0045] The first characteristic of the aerosol determined by the controller may relate to an intensity of the electromagnetic radiation received by the receiver. The controller may be configured to compare the first intensity of the electromagnetic radiation to a second intensity of the electromagnetic radiation.

[0046] The first intensity may correspond to an intensity of electromagnetic radiation received by the receiver after passage of an aerosol generated by the aerosol generation system that is drawn through the airflow channel. The controller may be configured to measure the first intensity based on a signal received from the receiver.

[0047] The second intensity may correspond to an intensity of the electromagnetic radiation when aerosol generated by the aerosol generation is not drawn through the airflow channel. The controller may be configured to measure the second intensity as a separate routine for determining the transmittance of the aerosol drawn through the airflow channel. For example, the second intensity may be measured by measuring an intensity of the electromagnetic radiation received at the receiver from the emitter when aerosol is not drawn through the airflow channel by the pump assembly. Measuring the second intensity may advantageously provide a means of calibrating the test fixture.

[0048] Alternatively, the second intensity may be a predetermined value stored in a memory of the controller.

[0049] The comparison of the first intensity to the second intensity may include the controller determining a ratio of the first intensity to the second intensity. The comparison of the first intensity to the second intensity may include the controller determining a transmittance of the electromagnetic radiation through the aerosol. In other words, the first characteristic of the aerosol determined by the controller may be the transmittance of the aerosol.

[0050] The absorbance of electromagnetic radiation by the aerosol is related to the transmittance. Specifically, the absorbance is equal to the negative base 10 logarithm of the transmittance. Thus, the controller may be configured to determine the absorbance in addition to or instead of the transmittance as the first property.

[0051] In other words, the first characteristic of the aerosol determined by the controller may be described as relating to the transmittance of the aerosol.

[0052] The sensing assembly may include a temperature sensor. The temperature sensor may be configured to measure a temperature of a portion of the airflow channel. The temperature sensor may include or consist of a thermocouple. The controller may be configured to determine a temperature of the aerosol drawn through the airflow channel based on a signal received from the temperature sensor. In other words, the second property of the aerosol determined by the controller may be temperature.

[0053] The generated aerosol drawn through the airflow channel may be cooled quickly to ambient temperature. Measuring the temperature of the generated aerosol after it has been cooled may have limited value, since all temperature measurements may be substantially the same, regardless of whether the aerosol generation system is defective. It may therefore be advantageous to position the temperature sensor towards the first channel opening. This may advantageously reduce the risk of cooling the generated aerosol to ambient temperature before it is drawn past the temperature sensor.

[0054] Preferably, the temperature sensor may be positioned closer to the first channel opening than any other component of the sensing assembly, for example, the temperature sensor may be positioned closer to the first channel opening than the emitter and receiver.

[0055] Preferably, the separation between the first channel opening and the temperature sensor when measured along the airflow channel may be less than 10 centimeters, preferably less than 5 centimeters, preferably less than 2 centimeters, even more preferably less than 1.5 centimeters.

[0056] The controller may be configured to determine that the aerosol-generation system is faulty if the second characteristic is not equal to one of the predefined values ​​for that characteristic or does not fall within one of the predefined ranges of values ​​for that characteristic. The temperature of the generated aerosol may depend on the temperature to which the substrate is heated. Overheating or underheating of the aerosol-forming substrate may cause the temperature of the generated aerosol to not equal to the predefined value or to fall within the predefined range of values. Overheating or underheating of the aerosol-forming substrate may indicate a fault in the aerosol-generation system.

[0057] The controller may advantageously be configured to compare the second characteristic to different predefined values ​​or ranges of predefined values ​​for successive puffs. This may be the case if the aerosol generating system is known to produce an aerosol temperature, preferably an average aerosol temperature, that varies with increasing number of puffs. For example, it may be known that the aerosol temperature decreases with increasing number of puffs. The controller may then advantageously be configured to compare the second characteristic to a predefined value or range of predefined values ​​that decreases for increasing number of puffs. In this way, the controller may advantageously be configured to determine a fault in the aerosol generating device if the temperature for successive puffs does not follow an expected pattern.

[0058] The sensing assembly may further comprise a pressure sensor. The pressure sensor may be configured to measure a pressure drop in a portion of the airflow channel. The controller may be configured to determine a pressure drop of the aerosol drawn through the airflow channel based on a signal received from the pressure sensor. In other words, the third property of the aerosol determined by the controller may be pressure.

[0059] The controller may advantageously be configured to compare the third characteristic to different predefined values ​​or ranges of predefined values ​​for successive puffs. This may be the case if the pressure drop of the aerosol generating system is known to vary with increasing number of puffs. For example, it may be known from previous experimentation that the pressure drop decreases with increasing number of puffs. In that case, the controller may advantageously be configured to compare the third characteristic to a predefined value or range of predefined values ​​that decreases for increasing number of puffs. In this way, the controller may advantageously be configured to determine a fault in the aerosol generating device if the pressure drop for successive puffs does not follow an expected pattern.

[0060] The emitter may comprise one or more LEDs. The emitter may comprise LEDs emitting electromagnetic radiation of different wavelengths. The emitter may be configured to emit electromagnetic radiation having a wavelength between 200 nanometers and 15,000 nanometers. Preferably, the emitter may be configured to emit electromagnetic radiation within the visible range of the electromagnetic spectrum. The emitter may be configured to emit electromagnetic radiation having a wavelength between 200 nanometers and 750 nanometers, preferably between 380 nanometers and 750 nanometers, preferably between 300 nanometers and 700 nanometers, even more preferably between 350 nanometers and 650 nanometers.

[0061] The receiver may comprise a fiber sensor. The receiver may be configured to receive electromagnetic radiation having a frequency corresponding to a frequency of the electromagnetic radiation emitted by the emitter.

[0062] The emitter may be configured to emit electromagnetic radiation into the airflow channel in a direction perpendicular to the direction of air flow drawn through the airflow channel when the test fixture is in the first configuration, the emitter and receiver are preferably positioned on opposite sides of the airflow channel.

[0063] In a second configuration of the test fixture, the pump assembly may be configured to draw air through the airflow channel in a second direction opposite to the first direction. The airflow in the second configuration may advantageously flush any remnants of the generated aerosol or other contaminants from the airflow channel. This may advantageously prepare the test fixture for determining at least one characteristic of the aerosol drawn through the airflow channel when the test fixture is in the first configuration (in other words, prepare the test fixture for the next puff). The air drawn through the airflow channel in the second configuration may be referred to as a purge airflow.

[0064] The airflow channel may further comprise a second channel opening. Air drawn in a second direction through the airflow channel may advantageously exit the airflow channel through the second channel opening. Thus, air that may carry previously generated aerosols and other contaminants advantageously does not have to pass back through the aerosol generation system, which may otherwise affect the outcome from later puffs. The second channel opening may be referred to as the outlet of the airflow channel.

[0065] The airflow channel may extend from the second channel opening. A first branch of the airflow channel may extend from the first channel opening and a second branch of the airflow channel may extend from the second channel opening. The first branch of the airflow channel may merge with the second branch of the airflow channel. The first branch of the airflow channel may merge with the second branch of the airflow channel upstream of the sensing assembly. Advantageously, air flowing through the airflow channel to or from either the first or second channel opening passes past the sensing assembly.

[0066] As used herein, the terms "upstream" and "downstream" are used to describe the relative location of a component or portion of a component of the test fixture with respect to a first direction, i.e., the direction in which the pump assembly draws air through the airflow channel when the test fixture is in the first configuration.

[0067] The test fixture may further include a valve assembly.

[0068] The valve assembly may be configured such that when the test fixture is in the first configuration, the first channel opening is open and the second channel opening is closed. Thus, aerosol generated by the aerosol generation system may not exit the airflow channel through the second channel opening in the first configuration. This may advantageously mean that when the test fixture is in the first configuration, the generated aerosol must be drawn past the sensing assembly. The generated aerosol may not bypass the sensing assembly by leaking out of the second channel opening when the second channel opening is closed.

[0069] The valve assembly may be configured such that when the test fixture is in the second configuration, the first channel opening is closed and the second channel opening is open. Thus, air drawn in the second direction through the airflow channel by the pump assembly may not exit the airflow channel through the first channel opening in the first configuration. As mentioned above, this may mean that previously generated aerosol and any contaminants do not pass through the first channel opening where the aerosol generation system is received. Hence, the purge airflow may advantageously not pass through the aerosol generation system received by the first channel opening.

[0070] The controller may be configured to control the valve assembly. The controller may be configured to control the pump assembly. The controller may be configured to control the valve assembly and the pump assembly to operate the test fixture between a first configuration and a second configuration. For example, in the first configuration, the controller may be configured to control the pump assembly to draw air in a first direction through the airflow channel, while also controlling the valve assembly to open the first channel opening and close the second channel opening.

[0071] The controller may be configured to operate the test fixture from the first configuration to the second configuration at the end of each individual puff. Alternatively, the controller may be configured to operate the test fixture from the first configuration to the second position after a number of consecutive puffs, for example, 4 or more, 5 or more, 6 or more puffs, 7 or more, 8 or more, 9 or more, 10 or more, 15 or more, or 20 or more puffs. This may correspond to a usage session of the aerosol generation system.

[0072] The valve assembly may comprise a first valve positioned between the first channel opening and the sensing assembly. When the airflow channel comprises a first branch and a second branch that meet upstream of the sensing assembly, the valve may be positioned upstream of a portion of the airflow channel where the first branch and the second branch meet. The first valve may be positioned in a portion of the first branch.

[0073] The first valve may be configured to open or close the first channel opening. The controller may be configured to control the first valve. The controller may be configured to open the first valve, at least initially, when the test fixture is in the first configuration. The controller may be configured to control the first valve at the end of a predetermined time period corresponding to the length of a puff. In this way, the first valve may advantageously be used to control when individual puffs begin and end while the test fixture is in the first position.

[0074] The first valve may be a pinch valve. Pinch valves may advantageously have relatively fast opening and closing times and may be simple to operate. Pinch valves may advantageously be particularly suitable for the first valve, as the first valve may need to be opened and closed frequently. Pinch valves may also be advantageous because they do not have metal or mechanical internal parts on which generated aerosols may accumulate.

[0075] The valve assembly may include a second valve positioned between the second channel opening and the sensing assembly. The controller may control the opening and closing of the second valve. When the airflow channel includes a first branch and a second branch that meet upstream of the sensing assembly, the second valve may be positioned upstream of a portion of the airflow channel where the first branch and the second branch meet. The second valve may be positioned in a portion of the second branch.

[0076] The second valve may be configured to open or close the second channel opening.

[0077] The second valve may be an electromechanically operated valve. The use of an electromechanical valve may be advantageous since it is not necessary to supply compressed air to operate the valve, as is the case for pinch valves.

[0078] A first channel opening or a second channel opening may be considered to be open when air can flow through the airflow channel, past the sensing assembly, and into or out of the respective channel opening. A first channel opening or a second channel opening may be considered to be closed when air cannot flow through the airflow channel, past the sensing assembly, and into or out of the respective channel opening. Thus, the first valve and the second valve may be considered to open or close the first channel opening and the second channel opening, respectively, even when the valve itself is not positioned at the channel opening.

[0079] In a third configuration of the test assembly, the pump assembly may be configured to draw air through the airflow channel in a first direction. When the test fixture is in the third configuration, the valve assembly may be configured to close the first channel opening. The valve assembly may be configured to open the second channel opening.

[0080] In the third configuration, air may be drawn from the second opening through the airflow channel, past the sensing assembly and towards the pump assembly. Air may not be drawn from the aerosol generation system into the airflow channel through the first opening. As in the second configuration, the airflow in the third configuration may advantageously flush any remaining generated aerosol or other contaminants from the airflow channel. This may advantageously prepare the test fixture to determine at least one characteristic of the aerosol drawn through the airflow channel when the test fixture is in the first configuration (in other words, prepare the test fixture for the next puff). The air drawn through the airflow channel in the third configuration may be referred to as a purge airflow.

[0081] The test facility may be configurable between a first configuration and at least one of a second or third configuration. Since both the second and third configurations provide purge airflow, configuring the test facility to be in only one of these configurations may be sufficient to flush the airflow channel of previously generated aerosols and contaminants after a test operation has been performed with the test facility in the first configuration. However, it may be preferred for the test facility to be configured in one of the second and third configurations and then later configured in the other configuration. In this way, purge airflow may be provided in both the first and second directions, which may advantageously flush the airflow channel more effectively.

[0082] The controller may be configured to control the valve assembly and the pump assembly to operate the test fixture between the first configuration and the third configuration, or between the second configuration and the third configuration.

[0083] The test fixture may include a first filter. The first filter may be configured to filter aerosols or contaminants in the air drawn through the airflow channel when the test fixture is in the second configuration. Preferably, the first filter may be configured to filter aerosols or contaminants in the air drawn through the airflow channel before the air passes through the second channel opening. The first filter may be located between the sensing assembly and the second channel opening. An advantage of providing such a first filter may be that aerosols or contaminants in the purge airflow do not pass through the second channel opening. This is particularly advantageous when the second channel is open to the atmosphere. By providing a filter, the test fixture may be located adjacent to a production line without emitting aerosols or contaminants into the atmosphere surrounding the production line.

[0084] Alternatively or additionally, the second channel opening may be connectable to a ventilation system or a waste container, which again may advantageously prevent aerosols or pollutants from being emitted into the atmosphere.

[0085] The airflow channel may further comprise a third channel opening. The airflow channel may extend from the first channel opening to the third channel opening. If the airflow channel further comprises a second airflow channel opening, the airflow channel may also extend from the second channel opening to the third channel opening. As mentioned above, this may be the case if the airflow channel includes a first branch and a second branch that merge together.

[0086] The third channel opening may be downstream of the sensing assembly. The third channel opening may be positioned such that air drawn through the airflow channel in the first direction by the pump assembly exits the airflow channel.

[0087] The pump assembly may include a first pump. The first pump may be positioned at or toward the third channel opening. The first pump may be configurable to draw air through the airflow channel in a first direction when the test fixture is in the first configuration. The first pump may be a suction pump.

[0088] The test fixture may include a second filter. The second filter may be configured to filter aerosols or contaminants in the air drawn through the airflow channel when the test fixture is in the first configuration. Preferably, the second filter may be configured to filter aerosols or contaminants in the air drawn through the airflow channel before the air passes through the third channel opening. The second filter may be located between the sensing assembly and the third channel opening. An advantage of providing such a second filter may be that aerosols or contaminants do not pass through the third channel opening. This is particularly advantageous when the third channel is open to the atmosphere. By providing a filter, the test fixture may be located adjacent to a production line without emitting aerosols or contaminants into the atmosphere surrounding the production line.

[0089] Alternatively or additionally, the third channel opening may be connectable to a further ventilation system or a waste container, again this may advantageously prevent aerosols or pollutants from being emitted into the atmosphere.

[0090] In the second configuration, air drawn by the pump assembly through the airflow channel in the second direction may enter the airflow channel through the third channel opening, which may be preferred if the third channel opening is open to atmosphere, in which case the first pump may be configurable to draw air through the airflow channel in the second direction when the test fixture is in the second configuration.

[0091] Alternatively, the airflow channel may include a fourth channel opening. Similar to the third channel opening, the fourth channel opening may be positioned downstream of the sensing assembly. The fourth channel opening may be positioned such that air drawn through the airflow channel in the second direction by the pump assembly exits the airflow channel through the fourth channel opening. The pump assembly may include a second pump positioned at or toward the fourth channel opening. The second pump may be configurable to draw air through the airflow channel in the second direction when the test fixture is in the second configuration.

[0092] The valve assembly may be configured such that when the test fixture is in the first configuration, the third channel opening is open and the fourth channel opening is closed. Thus, an aerosol generated by the aerosol generation system may exit the airflow channel through the third channel opening in the first configuration. The aerosol may not exit the airflow channel through the fourth channel opening in the first configuration. If the third channel opening is connectable to a further ventilation system or a waste container, this may advantageously ensure that any generated aerosol enters the ventilation system or waste container rather than exiting into the atmosphere. This is particularly the case when the test fixture is located adjacent to a production line.

[0093] The valve assembly may be configured such that when the test fixture is in the second configuration, the third channel opening is closed and the fourth channel opening is open. Thus, air drawn by the pump assembly through the airflow channel in the second direction may enter the airflow channel through the fourth channel opening in the third configuration. Air may not enter the airflow channel through the third channel opening in the second configuration. This may be particularly advantageous where the third channel opening is connectable to a ventilation system or a waste receptacle.

[0094] The valve assembly may be configured such that when the test fixture is in the third configuration, the third channel opening is closed and the fourth channel opening is open. Thus, air drawn in a first direction through the airflow channel by the pump assembly may enter the airflow channel through the second channel opening and may exit the airflow channel through the fourth channel opening in the second configuration. Air may not enter the airflow channel through the third channel opening in the second configuration.

[0095] The airflow channel may extend from a third channel opening and a fourth channel opening. A third branch of the airflow channel may extend from the third channel opening and a fourth branch of the airflow channel may extend from the fourth channel opening. The third branch of the airflow channel may merge with the fourth branch of the airflow channel. The third branch of the airflow channel may merge with the fourth branch of the airflow channel downstream of the sensing assembly.

[0096] If the airflow channel includes a fourth channel opening, the valve assembly may include a third valve positioned between the sensing assembly and the third channel opening. If the airflow channel includes a third branch and a fourth branch that meet downstream of the pump assembly, the third valve may be positioned downstream of a portion of the airflow channel where the third branch and the fourth branch meet. The third valve may be positioned in a portion of the third branch.

[0097] The valve assembly may include a fourth valve positioned between the sensing assembly and the fourth channel opening. If the airflow channel includes a third branch and a fourth branch that meet downstream of the pump assembly, the fourth valve may be positioned downstream of a portion of the airflow channel where the third branch and the fourth branch meet. The fourth valve may be positioned in a portion of the fourth branch.

[0098] The third valve may be configured to open or close the third channel opening.

[0099] The fourth valve may be configured to open or close the fourth channel opening.

[0100] The controller may be configured to operate the third valve and the fourth valve to open or close.

[0101] The test facility may be for analyzing aerosols generated by multiple aerosol generating systems. This may advantageously allow multiple systems to be tested at once. This may be particularly preferred when the test facility is used adjacent to a production line for manufacturing aerosol generating systems, or consumables for aerosol generating systems. This may be because multiple aerosol generating systems or consumables may need to be tested batch by batch in a quality assurance routine. Test facility for analyzing aerosols generated by multiple aerosol generating systems may advantageously speed up the quality assurance routine. For example, the test facility may advantageously be able to analyze aerosols generated from each of multiple aerosol generating systems or consumables at once as needed for a quality assurance routine.

[0102] The test fixture may comprise a first channel opening and a sensing assembly for each of a plurality of aerosol generation systems to be tested. For example, if the test fixture is suitable for analyzing aerosols generated by five different aerosol generation systems, the test fixture may comprise five first channel openings, each of the channel openings configured to receive a mouthpiece of one of the aerosol generation systems. The test fixture may further comprise five sensing assemblies comprising an emitter and a receiver. Such a test fixture may advantageously allow multiple aerosol generation systems to be tested simultaneously.

[0103] The test fixture may include a first channel opening for each of the plurality of aerosol generation systems and a single sensor assembly. The airflow channel may include a first branch associated with each of the first channel openings. Each of the first branches of the airflow channel may be connectable to a sensor assembly.

[0104] The test fixture may include an actuation mechanism configured to connect and disconnect each of the first branches of the airflow channel to the sensor assembly. In this manner, a single sensor assembly may be advantageously used to analyze aerosols generated by an aerosol generation system received in each of the first channel openings. This may advantageously reduce the cost, complexity, and size of the test fixture.

[0105] The actuation mechanism may be configured to sequentially connect and disconnect each of the first branches of the airflow channel to the sensor assembly. The actuation mechanism may comprise a rotary valve mechanism. The rotary valve mechanism may be configured to sequentially connect each of the first branches of the sensor assembly to the sensor assembly.

[0106] The rotary valve mechanism may comprise a single opening. The single opening may be formed in a rotatable element, such as a rotating disk. A first branch may be connected to the sensor assembly through the single opening. The rotatable element may otherwise prevent connection of the other branches to the sensor assembly. In this way, the rotatable element may be advantageously used to sequentially connect the individual branches to the sensor assembly.

[0107] The pump assembly in the first configuration may be configured to draw air in a first direction through the airflow channel when the first branch is connected to the sensor assembly In this manner, any aerosol generated by the aerosol generation system, as described above, may be drawn past the sensor assembly.

[0108] The test setup may further comprise a second channel opening. Preferably, the test setup may further comprise a second channel opening for each of the plurality of aerosol generation systems or each of the first channel openings. The airflow channel may comprise a second branch associated with each of the second channel openings. The actuation mechanism may be configured to sequentially connect and disconnect the, or each, second branch of the airflow channel to the sensor assembly. Preferably, the actuation mechanism may be configured to connect that or the second branch of the airflow channel after disconnecting it from one of the first sub-branches.

[0109] The pump assembly in the second configuration may be configured to draw air in a second direction through the airflow channel when the second branch is connected to the sensor assembly In this manner, a purge airflow may be advantageously drawn through the sensor assembly.

[0110] The test fixture may include a single second channel opening.

[0111] As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate is part of an aerosol-generating article.

[0112] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. For example, the aerosol-generating article may be an article that generates an aerosol that can be directly inhaled by a user sucking or puffing on a mouthpiece at the proximal or user end of the system. The aerosol-generating article may be disposable. An article comprising an aerosol-forming substrate containing tobacco is referred to as a tobacco stick. The aerosol-generating article may be insertable into a cavity of an aerosol-generating device.

[0113] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-generating article to generate an aerosol.

[0114] As used herein, the term "aerosol-generating system" refers to the combination of an aerosol-generating article with an aerosol-generating device as further described and illustrated herein. In the system, the aerosol-generating article and the aerosol-generating device cooperate to generate a respirable aerosol. Alternatively, the term "aerosol-generating system" refers to the aerosol-generating article itself, where the aerosol-generating article itself comprises a heat source, such as a carbonaceous combustible heat source.

[0115] The aerosol-forming substrate may comprise nicotine. The nicotine-containing aerosol-forming substrate may be a nicotine salt matrix. The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material comprising volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise a homogenized plant-derived material. The aerosol-forming substrate may comprise a homogenized tobacco material. The homogenized tobacco material may be formed by agglomerating particulate tobacco. In a particularly preferred embodiment, the aerosol-forming substrate may comprise an assembly of crimped sheets of homogenized tobacco material. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations.

[0116] The aerosol-forming substrate may include at least one aerosol former. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense and stable aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the system. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate, etc.), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). A preferred aerosol former is a polyhydric alcohol or mixtures thereof (such as triethylene glycol, 1,3-butanediol, etc.). Preferably, the aerosol former is glycerin. When present, the homogenized tobacco material may have an aerosol former content of 5 weight percent or more on a dry weight basis, and preferably has an aerosol former content of 5 weight percent to 30 weight percent on a dry weight basis. The aerosol-forming substrate may contain other additives and ingredients, such as flavourants.

[0117] The aerosol-generating article may comprise an outer paper wrapper. Additionally, the aerosol-generating article may comprise a separation between the aerosol-forming substrate and the filter plug. The separation may be approximately 18 millimeters, but may be in the range of approximately 5 millimeters to approximately 25 meters.

[0118] In a second aspect of the present disclosure, there is provided a method of analysing an aerosol generated by an aerosol generation system comprising an aerosol-forming substrate and a mouthpiece, using the test setup of the first aspect.

[0119] The method may include positioning a mouthpiece of the aerosol generation system such that the mouthpiece is received within the first channel opening.

[0120] The method may include using a pump assembly to draw air in a first direction through the airflow channel when the test fixture is in a first configuration, thereby drawing an aerosol generated by the aerosol generation system through the airflow channel.

[0121] The method may include determining at least one characteristic of the aerosol drawn through the airflow channel based on the signal received from the sensing assembly.

[0122] The method may include comparing the at least one determined characteristic to one or more predetermined values ​​for the at least one characteristic, or to one or more predetermined ranges of values ​​for the at least one characteristic.

[0123] The method may include determining that the aerosol generation system or aerosol-forming substrate is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0124] The step of determining at least one characteristic may include determining a first characteristic related to an intensity of the electromagnetic radiation received by the receiver.

[0125] Determining the first characteristic may include comparing a first intensity of the electromagnetic radiation to a second intensity of the electromagnetic radiation.

[0126] The first intensity may correspond to an intensity of electromagnetic radiation received by the receiver after passage of an aerosol generated by the aerosol generation system that is drawn through the airflow channel. The method may include measuring the first intensity based on a signal received from the receiver.

[0127] The second intensity may correspond to an intensity of the electromagnetic radiation when aerosol generated by the aerosol generation is not drawn through the airflow channel. The method may include measuring the second intensity as a separate routine for determining the transmittance of the aerosol drawn through the airflow channel. For example, the second intensity may be measured by measuring an intensity of the electromagnetic radiation received at the receiver from the emitter when aerosol is not drawn through the airflow channel by the pump assembly. Measuring the second intensity may advantageously provide a means of calibrating the test fixture. Alternatively, the second intensity may be a predetermined value stored in a memory of the controller.

[0128] Comparing the first intensity to the second intensity may include determining a ratio of the first intensity to the second intensity.

[0129] The first property may be the transmittance of electromagnetic radiation through the aerosol.

[0130] The step of determining the at least one characteristic may include determining a second characteristic. The second characteristic may be a temperature of the aerosol. The step of determining the second characteristic may include measuring a temperature of the aerosol using a temperature sensor of the sensing assembly.

[0131] The method may include determining that the aerosol generation system is faulty if the second characteristic is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0132] The method may advantageously include comparing the second property to different predetermined values ​​or ranges of predetermined values ​​for successive puffs.

[0133] The step of determining the at least one characteristic may comprise determining a third characteristic. The third characteristic may be a pressure drop of the aerosol. The step of determining the third characteristic may comprise measuring the pressure drop of the aerosol using a pressure sensor of the sensing assembly. The pressure sensor may advantageously be a differential pressure sensor.

[0134] The method may include determining that the aerosol generation system is faulty if the third characteristic is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0135] The method may advantageously include comparing the third property to different predetermined values ​​or ranges of predetermined values ​​for successive puffs.

[0136] The method may include drawing air through the airflow channel in a second direction, opposite the first direction, using the pump assembly when the test fixture is in the second configuration.

[0137] The test fixture may comprise a second channel opening. Air drawn in a second direction through the airflow channel may advantageously exit the airflow channel through the second channel opening.

[0138] The test fixture may further include a valve assembly.

[0139] The method may include configuring the test fixture in a first configuration by opening a first channel opening (or maintaining the first channel opening open) and closing a second channel opening (or maintaining the second channel opening closed) using a valve assembly. The method may further include drawing air in a first direction through the airflow channel using a pump assembly.

[0140] The method may include configuring the test fixture in a second configuration by closing the first channel opening (or maintaining the first channel opening closed) and opening the second channel opening (or maintaining the second channel opening open) using the valve assembly. The method may further include drawing air in a second direction through the airflow channel using the pump assembly.

[0141] The method may include configuring the test fixture in a third configuration by closing the first channel opening (or maintaining the first channel opening closed) and opening the second channel opening (or maintaining the second channel opening open) using the valve assembly. The method may further include drawing air in the first direction through the airflow channel using the pump assembly.

[0142] The method may include reconfiguring the test fixture from the first configuration to the second position at the end of each individual puff, preferably at the end of a predetermined time.

[0143] Alternatively, the method may include reconfiguring the test fixture from the first configuration to the second configuration after a number of consecutive puffs, for example, 4 or more, 5 or more, 6 or more puffs, 7 or more, 8 or more, 9 or more, 10 or more, 15 or more, or 20 or more puffs.

[0144] Opening or closing the first channel opening may include controlling a first valve to be open or closed.

[0145] Opening or closing the channel opening may include controlling a second valve to be open or closed.

[0146] The method may include controlling the first valve to close the first channel opening at the end of a predetermined time period. In this manner, the first valve may advantageously be used to control when individual puffs begin and end while the test fixture is in the first position.

[0147] The method may include reconfiguring the test fixture from a first configuration and at least one of a second configuration or a third configuration. Since both the second and third configurations provide purge airflows, reconfiguring the test fixture to be in only one of these configurations may be sufficient to flush previously generated aerosols and contaminants of the airflow channels after a test operation has been performed with the test fixture in the first configuration. However, the test fixture may preferably be reconfigured from the first configuration to one of the second and third configurations and then later reconfigured in the other configuration. In this way, purge airflows may be provided in both the first and second directions, which may advantageously flush the airflow channels more effectively.

[0148] The method may include activating the aerosol generation system prior to or simultaneously with performing the step of using the pump assembly to draw air through the airflow channel.

[0149] For electrically heated aerosol generating systems that include an aerosol generating device for electrically heating the aerosol-forming substrate, the step of activating the aerosol generating system may include activating the device. The aerosol generating device may perform a pre-heating routine during which no substantial amount of aerosol is generated. In that case, the step of activating the aerosol generating system may preferably be performed prior to carrying out the step of using the pump assembly.

[0150] The aerosol generating device may comprise a button or other user interface element that may be pressed to activate the device. Thus, activating the device may comprise pressing or interacting with a button or user interface element of the aerosol generating device. Activating the device may comprise a user manually pressing or interacting with a button or user interface element of the aerosol generating device. Alternatively, activating the device may comprise an actuation assembly of the test fixture that automatically interacts with a button or user interface element of the aerosol generating device when the aerosol generating device is to be activated. The actuation assembly may comprise a pneumatically actuable element configured to move between at least a first position in which the actuable element does not press or interact with the button or user interface element, and a second position in which the actuable element presses or interacts with the button or user interface element.

[0151] Alternatively, or additionally, the aerosol generating device may include a puff detection assembly. The puff detection assembly may be configured to activate the device upon detection of a puff. For example, the puff detection assembly may include a pressure sensor and may detect a puff based on a change in pressure indicative of a user taking a puff. Preferably, when the aerosol generating device includes a puff detection assembly, the method may include activating the aerosol generating device simultaneously with the step of using the pump assembly. Air drawn by the pump assembly may advantageously be detected by the puff detection assembly, whereby the aerosol generating system is automatically activated.

[0152] The aerosol generating system may comprise an aerosol-generating article comprising a combustible heat source and an aerosol-generating substrate. In such a case, activating the aerosol generating system may include igniting the combustible heat source. The step of activating the aerosol generating system may be performed simultaneously with the step of using the pump assembly. In this manner, air may be drawn through the aerosol generating system when the carbonaceous heat source is ignited, which may advantageously ensure proper ignition of the heat source.

[0153] In a third aspect of the present disclosure, a method for detecting defects in an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece is provided.

[0154] The method may include positioning a mouthpiece of the aerosol generating device such that the mouthpiece is received within a first channel opening of an airflow channel of the test fixture.

[0155] The method may include using a pump assembly of the test equipment to draw air in a first direction through the airflow channel, whereby an aerosol generated by the aerosol generation system is drawn from a mouthpiece received within the first channel opening and through the airflow channel.

[0156] As described with respect to the first aspect, the pump assembly may advantageously mimic a user inhaling into the mouthpiece of the aerosol generation system in a manner corresponding to real-world use of the system. Preferably, the pump assembly may draw air in a first direction through the airflow channel for a predetermined time and then stop drawing air in the first direction through the airflow channel. This may be referred to as a puff. The pump assembly may be configured to perform successive puffs. The pump assembly may advantageously draw air through the airflow channel in a reproducible manner, such that each "puff" is the same for each puff. In this way, reproducible results may be achieved for different aerosol generation systems or different puffs of the same aerosol generation system.

[0157] The method may include determining at least one characteristic of the aerosol drawn through the airflow channel.

[0158] The method may include comparing at least one determined characteristic to one or more predetermined values ​​for the or each characteristic, or to one or more predetermined ranges of values ​​for the or each characteristic.

[0159] The method may include determining that the aerosol generating system is faulty if at least one of the determined characteristics is not equal to one of the predefined values ​​for that characteristic or does not fall within one of the predefined ranges of values ​​for that characteristic. Determining a faulty system based on a comparison of the determined characteristics to predefined values ​​may advantageously mean that the controller does not need to carry out a detailed analysis of the generated aerosol to determine a faulty device. For example, the first characteristic may be the transmittance of the aerosol as measured using the sensing assembly. The generated aerosol of a properly operating aerosol generating system may have a transmittance that corresponds to a predefined value or range of values. Thus, the controller may advantageously determine a faulty system if the transmittance is not equal to the predefined value or does not fall within the range of values. The transmittance of the aerosol may depend at least on the amount of aerosol generated and the chemical composition of the generated aerosol, but advantageously the controller does not need to determine the amount or chemical composition of the generated aerosol.

[0160] The one or more predetermined values ​​or the one or more ranges of predetermined values ​​may advantageously be values ​​determined by previous experimentation in which a threshold value for an expected value between a properly operating aerosol generating system and a defective aerosol generating system has been determined.

[0161] The method may further include determining a predetermined value or range of values, which may include determining one or more characteristics of each of the aerosols of the aerosol generating system known to operate correctly with a separate routine, and the value for the characteristic may be used as the predetermined value.

[0162] The at least one property may include a first property. The first property may be a transmittance of electromagnetic radiation through the aerosol.

[0163] The method may include determining a first characteristic, which may include comparing a first intensity of the electromagnetic radiation to a second intensity of the electromagnetic radiation.

[0164] The first intensity may correspond to an intensity of electromagnetic radiation received by the receiver after passage of an aerosol generated by the aerosol generation system that is drawn through the airflow channel. The method may include measuring the first intensity based on a signal received from the receiver.

[0165] The second intensity may correspond to an intensity of the electromagnetic radiation when aerosol generated by the aerosol generation is not drawn through the airflow channel. The method may include measuring the second intensity as a separate routine for determining the transmittance of the aerosol drawn through the airflow channel. For example, the second intensity may be measured by measuring an intensity of the electromagnetic radiation received at the receiver from the emitter when aerosol is not drawn through the airflow channel by the pump assembly. Measuring the second intensity may advantageously provide a means of calibrating the test fixture. Alternatively, the second intensity may be a predetermined value stored in a memory of a controller of the test fixture.

[0166] Comparing the first intensity to the second intensity may include determining a ratio of the first intensity to the second intensity.

[0167] The first property may be the transmittance of electromagnetic radiation through the aerosol.

[0168] The step of determining the at least one characteristic may include determining a second characteristic. The second characteristic may be a temperature of the aerosol. The step of determining the second characteristic may include measuring a temperature of the aerosol using a temperature sensor of the sensing assembly.

[0169] The method may include determining that the aerosol generation system is faulty if the second characteristic is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0170] The method may advantageously include comparing the second property to different predetermined values ​​or ranges of predetermined values ​​for successive puffs.

[0171] The step of determining the at least one characteristic may include determining a third characteristic. The third characteristic may be a pressure drop of the aerosol. The step of determining the third characteristic may include measuring the pressure drop of the aerosol using a pressure sensor of the sensing assembly.

[0172] The method may include determining that the aerosol generation system is faulty if the third characteristic is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0173] The method may advantageously include comparing the third property to different predetermined values ​​or ranges of predetermined values ​​for successive puffs.

[0174] Features described with respect to one aspect, example or embodiment may also be applicable to other example aspects and embodiments. In particular, features of the test setup of the first aspect may be applied to the test setup used in the methods of the second and third aspects. Similarly, features described with respect to the method of the second aspect may also be applied to the method of the third aspect and vice versa.

[0175] Below is provided a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features of the other examples, embodiments, or aspects described herein.

[0176] [Example 1] 1. A test fixture for analyzing an aerosol generated by an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, comprising: an airflow channel extending from the first channel opening configured to receive a mouthpiece of the aerosol generation system; a sensing assembly comprising an emitter configured to emit electromagnetic radiation into the airflow channel and a receiver configured to receive at least a portion of the electromagnetic radiation from the airflow channel; a pump assembly in a first configuration of the test fixture, the pump assembly being configured to draw air in a first direction through the airflow channel such that, in use, an aerosol generated by the aerosol generation system is drawn from a mouthpiece received within the first channel opening and through the airflow channel; and a controller configured to determine at least one characteristic of the aerosol drawn through the airflow channel based on a signal received from the sensing assembly.

[0177] [Example 2] A test setup according to Example 1, wherein the sensing assembly is positioned between the first channel opening and the pump assembly.

[0178] [Example 3] The test setup according to example 1 or example 2, wherein the controller is configured to compare the at least one determined characteristic with one or more predefined values ​​for the or each characteristic, or with one or more predefined ranges of values ​​for the or each characteristic.

[0179] [Example 4] A testing facility according to Example 3, wherein the controller is configured to determine that the aerosol generation system is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0180] [Example 5] A test setup according to any one of the preceding embodiments, wherein the first property of the aerosol determined by the controller relates to the intensity of electromagnetic radiation received by the receiver.

[0181] [Example 6] A test setup according to Example 5, wherein the controller is configured to compare a first intensity of electromagnetic radiation to a second intensity of electromagnetic radiation, the first intensity corresponding to the intensity of the electromagnetic radiation when received by the receiver after passing through an aerosol generated by the aerosol generation system that is drawn through the airflow channel, and the second intensity corresponding to the intensity of the electromagnetic radiation when the aerosol generated by the aerosol generation system is not drawn through the airflow channel.

[0182] [Example 7] 7. The testing setup according to example 6, wherein the comparison of the first intensity to the second intensity includes a controller that determines a ratio of the first intensity to the second intensity.

[0183] [Example 8] The test setup according to example 6 or example 7, comprising a controller where a comparison of the first intensity and the second intensity determines a transmission rate of the electromagnetic radiation through the aerosol.

[0184] [Example 9] The test setup according to any one of Examples 6 to 8, wherein the controller is configured to measure a first strength based on the signal received from the receiver.

[0185] [Example 10] The test fixture according to any one of the preceding embodiments, wherein the sensing assembly further comprises a temperature sensor configured to measure a temperature of a portion of the airflow channel.

[0186] [Example 11] The test setup according to Example 10, wherein the temperature sensor is a thermocouple.

[0187] [Example 12] The test setup according to example 10 or example 11, wherein the second property of the aerosol determined by the controller is temperature.

[0188] [Example 13] The test fixture according to any one of the preceding embodiments, wherein the sensing assembly further comprises a pressure sensor, preferably a differential pressure sensor, configured to measure a pressure drop in a portion of the airflow channel.

[0189] [Example 14] A test setup according to Example 13, wherein a third property of the aerosol determined by the controller is pressure drop.

[0190] [Example 15] A test fixture according to any one of the preceding embodiments, wherein the emitter comprises one or more LEDs.

[0191] [Example 16] A test setup according to any one of the preceding embodiments, wherein the receiver comprises a fiber sensor.

[0192] [Example 17] A testing setup according to any one of the preceding embodiments, wherein the emitter is configured to emit electromagnetic radiation having a wavelength between 200 nanometers and 15,000 nanometers.

[0193] [Example 18] A test setup according to any one of the preceding embodiments, wherein the receiver is configured to receive electromagnetic radiation having a wavelength between 200 nanometers and 15,000 nanometers.

[0194] [Example 19] A testing arrangement according to any one of the preceding embodiments, wherein the emitter is configured to emit electromagnetic radiation into the airflow channel in a direction perpendicular to the direction of air flow drawn through the airflow channel when the testing arrangement is in the first configuration.

[0195] [Example 20] A test fixture according to any one of the preceding embodiments, wherein the emitter and receiver are positioned on opposite sides of the airflow channel.

[0196] [Example 21] A testing fixture according to any one of the preceding embodiments, wherein in a second configuration of the testing fixture, the pump assembly is configured to draw air through the airflow channel in a second direction opposite to the first direction.

[0197] [Example 22] A test fixture according to Example 21, wherein the airflow channel further comprises a second channel opening.

[0198] [Example 23] The test setup according to example 22, wherein the test setup further comprises a valve assembly.

[0199] [Example 24] 24. A test fixture according to example 23, wherein the valve assembly is configured such that when the test fixture is in the first configuration, the first channel opening is open and the second channel opening is closed.

[0200] [Example 25] The test fixture according to example 23 or example 24, wherein the valve assembly is configured such that when the test fixture is in the second configuration, the first channel opening is closed and the second channel opening is open.

[0201] [Example 26] A test setup according to example 24 or example 25, wherein the valve assembly comprises a first valve positioned between the first channel opening and the sensing assembly, the first valve being configured to open or close the first channel opening.

[0202] [Example 27] The test setup according to Example 26, wherein the first valve is a pinch valve.

[0203] [Example 28] A test setup according to any one of Examples 24 to 27, wherein the valve assembly comprises a second valve positioned between the second channel opening and the sensing assembly, the second valve being configured to open or close the second channel opening.

[0204] [Example 29] The test setup according to Example 28, wherein the second valve is an electromechanically operated valve.

[0205] [Example 30] A test setup according to any one of Examples 23 to 29, wherein in a third configuration of the test assembly, the pump assembly is configured to draw air through the airflow channel in a second direction opposite to the first direction, and the valve assembly is configured to close the first channel opening when the test setup is in the third configuration.

[0206] [Example 31] 11. A method for analysing an aerosol generated by an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, using a test setup according to any one of the preceding claims, comprising the steps of: Positioning a mouthpiece of the aerosol generation system such that the mouthpiece is received within the first channel opening; drawing air in a first direction through the airflow channel using the pump assembly when the test fixture is in the first configuration, whereby an aerosol generated by the aerosol generation system is drawn from a mouthpiece received within the first channel opening and through the airflow channel; and determining at least one characteristic of the aerosol drawn through the airflow channel based on the signal received from the sensing assembly.

[0207] [Example 32] 32. The method according to example 31, further comprising comparing the at least one determined characteristic to one or more predetermined values ​​for the at least one characteristic or to one or more predetermined ranges of values ​​for the at least one characteristic.

[0208] [Example 33] The method according to Example 32, further comprising determining that the aerosol generation system or the aerosol-forming substrate is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0209] [Example 34] The method according to any one of Examples 31-33, wherein the step of determining at least one characteristic includes determining a first characteristic related to an intensity of the electromagnetic radiation received by the receiver.

[0210] [Example 35] 35. The method according to example 34, wherein the step of determining the first characteristic includes comparing a first intensity of the electromagnetic radiation to a second intensity of the electromagnetic radiation, the first intensity corresponding to an intensity of the electromagnetic radiation received by the receiver and the second intensity corresponding to an intensity of the electromagnetic radiation emitted by the emitter.

[0211] [Example 36] The method according to example 35, wherein comparing the first intensity and the second intensity comprises determining a ratio of the first intensity to the second intensity.

[0212] [Example 37] The method according to any one of Examples 34 to 36, wherein the first property is the transmittance of electromagnetic radiation through the aerosol.

[0213] [Example 38] The method according to any one of Examples 31 to 37, wherein the step of determining at least one property comprises determining a second property, and the second property is a temperature of the aerosol.

[0214] [Example 39] The method according to any one of Examples 31 to 38, wherein the step of determining at least one property includes determining a third property, and the third property is a pressure drop of the aerosol.

[0215] [Example 40] The method according to any one of Examples 31 to 39, wherein the method further includes using a pump assembly in a second configuration of the test fixture to draw air through the airflow channel in a second direction opposite to the first direction.

[0216] [Example 41] The method according to example 40, wherein the step of using the pump assembly in the second configuration occurs after the step of using the pump assembly in the first configuration.

[0217] [Example 42] The method according to example 41, wherein the step of using the pump assembly in the second configuration includes closing the first channel opening and opening the second channel opening.

[0218] [Example 43] 1. A method for detecting a defect in an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, comprising: positioning a mouthpiece of an aerosol generating device such that the mouthpiece is received within a first channel opening of an airflow channel of the test fixture; using a pump assembly of the test fixture to draw air in a first direction through the airflow channel, whereby an aerosol generated by the aerosol generation system is drawn from a mouthpiece received within the first channel opening and through the airflow channel; determining at least one characteristic of the aerosol drawn through the airflow channel; comparing the at least one determined characteristic to one or more predetermined values ​​for the or each characteristic or to one or more predetermined ranges of values ​​for the or each characteristic; and determining that the aerosol generation system is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

[0219] [Example 44] The method according to example 43, wherein the at least one property comprises a first property that is a transmittance of electromagnetic radiation through the aerosol.

[0220] [Example 45] The method according to example 43 or example 44, wherein the at least one property comprises a second property that is a temperature of the aerosol.

[0221] [Example 46] The method according to any one of Examples 43-45, wherein the at least one characteristic includes a third characteristic that is a pressure of the aerosol. The embodiments will now be further described with reference to the figures. [Brief description of the drawings]

[0222] [Figure 1] FIG. 1 is a schematic diagram of a test setup according to a first embodiment in combination with a first aerosol generation system. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the first aerosol generation system of FIG. [Diagram 3] FIG. 3 is a flow diagram of a method for analyzing aerosol generated by the first aerosol generation system of FIG. 2 using the test fixture of FIG. [Figure 4] FIG. 4 is a schematic diagram of the test setup of FIG. 1 in a first configuration. [Diagram 5] FIG. 5 is a graph showing the transmittance of the aerosol generated when using the first aerosol generating system of FIG. 1 for successive puffs. [Figure 6] FIG. 6 is a graph depicting the temperature of the aerosol generated when using the aerosol generating system of FIG. 1 for successive puffs. [Figure 7] FIG. 7 is a schematic diagram of the test setup of FIG. 1 in a second configuration. [Figure 8] FIG. 8 is a schematic diagram of the test setup of FIG. 1 in a third configuration. [Figure 9] FIG. 9 is a schematic diagram of a second embodiment of a test setup suitable for analyzing aerosols generated by two aerosol generation systems. [Figure 10] FIG. 10 is a schematic diagram of a third embodiment of a test fixture suitable for analyzing aerosols generated by two aerosol generation systems, the test fixture in a first position. [Figure 11] FIG. 11 is a schematic diagram of a third embodiment of the test fixture, the test fixture being in a second position.

[0223] Figure 1 is a schematic diagram of a test fixture 100 in which a first aerosol generation system 200 is received. The aerosol generation system 200 is shown in more detail in Figure 2 as a cross-sectional schematic diagram, separate from the test fixture 100.

[0224] The test fixture 100 includes an airflow channel 102 .

[0225] The first branch 104 of the airflow channel extends from a first channel opening 105 configured to receive a mouthpiece of the aerosol generation system 200. The first channel opening 105 includes a machined mouthpiece receiving portion (not shown in the figures) shaped to receive the mouthpiece of the aerosol generation system 200 within the opening of the mouthpiece receiving portion and to provide a seal between the test fixture and the mouthpiece of the aerosol generation system 200. The mouthpiece of the aerosol generation system 200 is received within the first channel opening 105 but is not shown in FIG. 1 as it is shown in FIG. 2 as feature 204.

[0226] A second branch 106 of the airflow channel extends from a second channel opening 107 that is open to the atmosphere. The first branch 104 and the second branch 106 meet at a first junction 108.

[0227] Between the first channel opening 105 and the first junction 108 is a first valve 112. The first valve 112 is a pinch valve and is controllable to be open or closed. When the first valve 112 is open, air can flow from the first channel opening 105, through the first branch 104, and then through the airflow channel 102 (or vice versa). When the first valve 112 is closed, air cannot flow from the first channel opening 105 and through the first branch 104 (or vice versa). When the first valve 112 is closed, the first channel opening 105 may be referred to as being closed.

[0228] Between the second channel opening 107 and the first junction 108 is a second valve 116. The second valve 116 is an electromechanically operated valve and is controllable to be open or closed. When the second valve 116 is open, air can flow from the second channel opening 107, through the second branch 106 and then through the airflow channel 102 (or vice versa). When the second valve 116 is closed, air cannot flow from the second channel opening 107 and through the second branch 106 (or vice versa). When the second valve 116 is closed, the second channel opening 107 may be referred to as being closed.

[0229] Downstream of the first junction 108, the airflow channel 108 passes through a sensing assembly 118 and continues to a second junction 113. Between the second junction 113 and the second valve 116, a filter element 121 is positioned.

[0230] The sensing assembly 118 includes an emitter 140 that includes a plurality of LEDs configured to emit electromagnetic radiation into the airflow channel. The electromagnetic radiation has a wavelength in the visible region of the electromagnetic spectrum. Specifically, the LEDs are configured to emit electromagnetic radiation at a single wavelength of 625 nanometers.

[0231] The sensing assembly 118 further comprises a receiver 142 in the form of a fiber sensor. The receiver 142 is configured to receive at least a portion of the electromagnetic radiation emitted by the emitter 140 into the airflow channel. The emitter 140 and the receiver 142 are positioned on opposite sides of the airflow channel 102. In this manner, the electromagnetic radiation received by the receiver 142 from the emitter 140 must pass through the airflow channel 102. Hence, the electromagnetic radiation must interact with the air within the airflow channel.

[0232] The sensing assembly 118 further comprises a temperature sensor 144. The temperature sensor 144 is a thermocouple. The temperature sensor is suitable for measuring temperatures between approximately minus 50 degrees Celsius and 350 degrees Celsius. The temperature sensor 144 is configured to measure the temperature of a portion of the airflow channel 102. In this manner, the temperature of the air flowing through the airflow channel 102 can be determined.

[0233] The sensing assembly 118 further includes a pressure sensor 146. The pressure sensor 146 is configured to measure a pressure drop across a portion of the airflow channel 102.

[0234] A third branch 122 of the airflow channel 102 extends from the second junction 113 to a third channel opening 124. The third channel opening 124 is open to the atmosphere.

[0235] A fourth branch 126 of the airflow channel 102 extends from the second junction 113 to a fourth channel opening 128. Again, the fourth channel opening 128 is open to the atmosphere.

[0236] Between the second junction 113 and the third channel opening 124, a third valve 130 and a first pump 132 are positioned. The third valve 130 is an electromechanical valve and can be controlled to be open or closed. When the third valve 130 is open, air can flow from the second junction 113, through the third branch 122, and then to the third channel opening 124 (or vice versa). When the third valve 130 is closed, air cannot flow from the second junction 113, through the third branch 122, and then to the third channel opening 124 (or vice versa). When the third valve 130 is closed, the third channel opening 124 may be referred to as being closed.

[0237] The first pump 132 is a suction pump. The first pump 132 is controllable to be either on or off. When the first pump 132 is controlled to be switched on, the first pump 132 is configured to draw air in a first direction through the airflow channel 102, such that air is drawn through the airflow channel to flow from the first junction 108 towards the second junction 113.

[0238] A fourth valve 134 and a second pump 136 are positioned between the second junction 113 and the fourth channel opening 128. The fourth valve 134 is an electromechanical valve and can be controlled to open or closed. When the fourth valve 134 is open, air can flow from the second junction 113 through the fourth branch 126 and then to the fourth channel opening 128 (or vice versa). When the fourth valve 134 is closed, air cannot flow from the second junction 113 through the fourth branch 126 and then to the fourth channel opening 128 (or vice versa). When the fourth valve 134 is closed, the fourth channel opening 128 may be referred to as being closed.

[0239] The second pump 136 may be referred to as an exhaust pump. The second pump 136 is controllable to be off, on in suction mode, or on in blow mode. When the second pump 136 is controlled to be switched on in suction mode, the second pump 136 is configured to draw air in a first direction through the airflow channel 102, whereby air is drawn through the airflow channel to flow from the first junction 108 towards the second junction 113. When the second pump 136 is controlled to be switched on in blow mode, the second pump 136 is configured to draw air in a second direction through the airflow channel 102, whereby air is drawn through the airflow channel to flow from the second junction 113 towards the first junction 108.

[0240] The first pump 132 and the second pump 136 together may be referred to as a pump assembly 138. The pump assembly 138 and the first valve 112, the second valve 116, the third valve 130 and the fourth valve 134 are controlled by a controller of the test assembly, not shown in the figures. The controller controls the first pump and the second pump to be switched on or off, and in the case of the second pump, is configured to be in a suction mode or a blowing mode when switched on. The controller is also configured to open or close the first, second, third and fourth valves as required. In particular, the controller controls the pump assembly and the valves according to different configurations of the test fixture, which will be described in more detail below.

[0241] Although the second, third, and fourth channel openings are all described as being open to the atmosphere, any or all of these openings could be connected to a ventilation system or waste container separate from the test fixture. This would ensure that any exhausted air from the test fixture is contained. In such an embodiment, it may not be necessary to include the filter element 121 in the test fixture 100. However, the presence of the filter element 121 would still provide the advantage of protecting the pump from generated aerosols.

[0242] Figure 2 is a cross-sectional schematic diagram of a first aerosol generation system 200, shown in Figure 1 in combination with the test fixture 100. The aerosol generation system 200 comprises an aerosol generation device 202 comprising a chamber 210 defined by an apparatus housing. The chamber 210 is tubular, made of stainless steel, and has a base at an upstream end. The chamber 210 is configured to receive an aerosol-generating article 300.

[0243] The aerosol-generating article 300 is received in the chamber 210, which contains the aerosol-forming substrate 306. The aerosol-forming substrate is a solid tobacco-containing substrate. Specifically, the aerosol-forming substrate is a collection of homogenized tobacco sheets. As shown in FIG. 2, the aerosol-generating article and the chamber are configured such that when the aerosol-generating article is received in the chamber, the mouth end of the aerosol-generating article 300 protrudes out of the chamber 10 and out of the aerosol generating device. This mouth end forms a mouthpiece 304. In normal use of the aerosol generating system 200, a user of the system may puff on the mouthpiece 304 during use. However, when the aerosol generating system 200 is used with the test fixture 100 of FIG. 1, the mouthpiece 304 is instead received in the first channel opening 105 of the test fixture 100.

[0244] The aerosol generating device 202 comprises a heater assembly comprising a heating element 211. The heating element 211 surrounds the chamber 10 along with a portion of the chamber in which the aerosol-forming substrate 306 of the aerosol-generating article 202 is received. The heating element 211 is a resistive heating element.

[0245] The airflow channel 220 extends from an air inlet 222 of the aerosol generating device 100. Upstream of the chamber, the airflow channel 220 is defined primarily by an airflow channel wall 224. Downstream of the airflow channel wall 224, the airflow channel 220 passes through an air inlet defined in the base of the chamber. The airflow channel 220 then extends through the chamber 210. Specifically, air flowing through the airflow channel 220 passes into the aerosol-generating article 300 at its distal end.

[0246] The aerosol generating device 202 further comprises a power source 242 in the form of a rechargeable battery for powering a heating element 211 that is controllable by a controller (not shown) of the device. The power source is connected to the controller and heating element 211 via wires and connections not shown in the figure. The aerosol generating device may comprise further elements not shown in the figure, such as a button for activating the aerosol generating device.

[0247] During use of the aerosol generating system 100, air is drawn through the mouthpiece 304 of the received aerosol-generating article 300, resulting in air being drawn through the airflow channel 220 towards the mouthpiece 304. Air will be drawn from the outside of the aerosol generating device into the airflow channel 220 through the air inlet 222. Since the aerosol-generating article 300 is received in a chamber, the air drawn into the chamber will enter the aerosol-generating article 300 at its distal end. Thus, the air passes through the aerosol-forming substrate 306. In doing so, the volatile compounds generated by the heating of the substrate 306 become entrained in the air. As the air continues towards the mouthpiece 304 of the aerosol-generating article 300, the volatile compounds cool and form an aerosol. The air and the entrained aerosol then exit the aerosol-generating article 300 through the mouthpiece 304.

[0248] In normal use of the aerosol generation system 200, as described above, it is the user puffing on the mouthpiece 304 that results in air being drawn through the airflow channel 220. During a puff, the user inhales through the aerosol generation system 100, thereby drawing air through the aerosol generation system 200.

[0249] 1, when the aerosol generation system 200 is used with the test fixture 100, the test fixture 100, and in particular the pump assembly 138 of the test fixture 100, mimics a user taking a puff and drawing air through the aerosol generation system 200. The purpose is for the generated aerosol to enter the airflow channel 102 and pass past the sensing assembly 118 of the test fixture 100 to be analyzed. Analysis of the generated aerosol allows for the detection of a defective aerosol generation system 200, and is particularly important in the context of quality assurance testing for the manufacture of the aerosol generation system 200 or components of that system, in particular consumable components of that system.

[0250] FIG. 3 shows a flow diagram illustrating the steps of analyzing the aerosol generated by the aerosol generation system of FIG. 2 using the test setup shown in FIG.

[0251] Step 402 of the method is to position the aerosol generation system 200 within the test fixture 100. Specifically, the mouthpiece 304 of the aerosol generation system is inserted into the mouthpiece receiving portion of the first channel opening 105 of the test fixture 100.

[0252] A step 404 of the method is to draw the generated aerosol into the test fixture 100 using the pump assembly 138. Step 404 first involves configuring the test fixture 100 of FIG. 1 in a first configuration, as shown in FIG. 4. A controller of the test fixture is configured to open the first valve 112 and the third valve 130, and close the second valve 116 and the fourth valve 134. If the valves are already in their respective open or closed states for the first configuration, the controller is configured to maintain the valves in that state. For example, if the first valve 112 is already open, the controller maintains the first valve in its open position.

[0253] The controller is also configured to turn on the first pump 132 to draw air in a first direction through the airflow channel. Because the second valve 116 and the fourth valve 134 are closed, air cannot enter the airflow channel 102 through the second channel opening 107 or the fourth channel opening 128. Therefore, when the first pump 132 draws air in a first direction through the airflow channel 102, the air must be drawn through the first channel opening 105 into the airflow channel 102 and therefore through the aerosol generation system 200, whose mouthpiece 204 is received in the first channel opening 105. The pump assembly 138 mimics a user inhaling the aerosol generation system 200. The airflow through the test fixture 100 in the first configuration is represented by dashed-dotted arrows in FIG. 4.

[0254] The aerosol generating system 200 is an electrically heated aerosol generating system, and therefore, in order to generate the aerosol, the aerosol generating device 202 should be activated to heat the aerosol. In some embodiments, the aerosol generating device 202 includes a button for activating the device, which should be pressed by the user to activate the device. This may be before or during the process in which the pump assembly draws air through the airflow channel. Alternatively, or additionally, in other embodiments, the aerosol generating device 200 includes a puff detector system configured to activate the device upon detecting a puff. In such an embodiment, the aerosol generating device 200 is automatically activated upon detection of a puff, and is therefore activated by the pump assembly 138 drawing air through the airflow channel 102.

[0255] When the aerosol generating device 202 is activated, the heater element 210 heats the aerosol-forming substrate 306 to generate an aerosol, as described above with respect to Figure 2. This generated aerosol is then entrained in air that is drawn through the airflow channel 102 by the pump assembly 138.

[0256] A step 406 of the method is to determine a characteristic of the generated aerosol. This step is performed by the test facility controller based on the signal received from the sensing assembly 118.

[0257] Step 406 involves determining a first property of the generated aerosol, which is the transmittance of the aerosol. The transmittance of a material is defined as the ratio of light energy transmitted through an object to the light energy that falls on the object. In this case, the object is the generated aerosol.

[0258] The light energy transmitted through the generated aerosol is determined by the controller based on the signal received from the receiver 142 as the generated aerosol is drawn through the airflow channel 102. This is because the generated aerosol passes through the sensing assembly 118, causing the electromagnetic radiation emitted by the emitter 140 to interact with (and be absorbed by) the aerosol. Thus, the intensity of the electromagnetic radiation received by the receiver 142 represents the amount of energy transmitted through the generated aerosol. This intensity is a first intensity.

[0259] In some embodiments, the light energy impinging on the generated aerosol is a predetermined value stored in a memory of the test facility controller. In some embodiments, the light energy impinging on the generated aerosol is alternatively or additionally measured prior to step 404. Specifically, the test facility controller is configured to measure the intensity of electromagnetic radiation from emitter 140 received at receiver 142 when no aerosol has yet been generated. This intensity is the second intensity.

[0260] The controller of the test fixture 100 is configured to determine the transmittance of the generated aerosol by calculating a ratio of the first intensity to the second intensity.

[0261] Method step 408 involves comparing the first characteristic (i.e., the determined transmittance) to a predetermined range of values ​​for the transmittance, the predetermined range of values ​​representing values ​​for the transmittance of an aerosol generated by a properly operating aerosol generation system.

[0262] The range of predetermined values ​​is a known value determined from previous experiments. For example, such experiments may include measuring the transmittance of aerosols generated by a large number of aerosol generation systems known to operate correctly (i.e., have no defects). The range of predetermined values ​​may then be determined based on the average of the transmittance values ​​and the spread or standard deviation of the transmittance values.

[0263] The predetermined range of values ​​used in the comparison is specific to the type of aerosol-generating system being tested and also to the type of aerosol-forming substrate of the aerosol-generating system being tested (if the aerosol-generating system has the capability of operating with different aerosol-forming substrates).

[0264] The predetermined value ranges are stored in a memory of the test equipment controller, and in some embodiments the method may additionally include, for example, manually entering the predetermined value ranges into the memory or by uploading the predetermined value ranges into the memory from a central database.

[0265] Step 408 includes step 409 of checking whether the characteristic is outside a predetermined range.

[0266] Method step 410 is executed if the determined characteristic is outside of a predetermined range of values ​​for that characteristic. Method step 410 is to determine that the aerosol generation system 200 is defective. If the aerosol generation system 200 is determined to be defective, the testing device 100 will inform the user. This may be via a user interface (not shown in the figures) of the testing device 100, for example in the form of an error message on the screen of the user interface, by emitting a sound, or by lighting an error LED on the user interface.

[0267] Method step 412 is executed if the determined characteristic is within a predetermined range of values ​​for that characteristic. Step 412 in FIG. 4 is to take no action. However, in some embodiments, the test device notifies the user that the aerosol generation system 200 being tested is not defective.

[0268] In some embodiments, step 412 is followed by repeating steps 406 and 408 for additional properties of the generated aerosol while the generated aerosol is being drawn into the test fixture 100. In some embodiments, the controller performs steps 406 and 408 for the additional properties simultaneously as for the first property.

[0269] In some embodiments, the method may include comparing the or each property against a respective single pre-defined value, rather than a range of pre-defined values. The principle is the same: the single pre-defined value is known from previous experimentation.

[0270] Steps 406 and 408 are repeated by determining a second property and a third property of the generated aerosol and comparing the second property and the third property to respective predetermined value ranges. The second property is the temperature of the generated aerosol. The third property is the pressure drop at which the aerosol is generated compared to ambient pressure.

[0271] The second characteristic is determined by the test fixture controller based on a signal received at the controller from the temperature sensor 144 .

[0272] The third characteristic is determined by the test fixture controller based on a signal received at the controller from pressure sensor 146. Pressure sensor 146 is a differential pressure sensor and therefore can directly determine the pressure drop within the airflow channel.

[0273] Again, the predetermined ranges of values ​​for the second and third properties are known values ​​derived from previous experimentation for the particular type of aerosol-generating system and aerosol-forming substrate being tested.

[0274] In some embodiments, the controller is configured to determine that the aerosol generation device is defective if any one of the first through third characteristics is outside a respective predetermined range, hi some embodiments, the controller is configured to determine that the aerosol generation device is defective only if two or three of the first through third characteristics are outside a respective predetermined range.

[0275] Steps 406 and 408 are performed (and repeated) simultaneously with step 404. Step 404 continues for a predetermined time period representative of a typical user's puff. The predetermined time period is 2 seconds. At the end of the predetermined time period, step 404 ends and the controller of the test fixture 100 is configured to turn off the first pump 132.

[0276] In some embodiments, the method includes repeating steps 404 and after of Figure 3 for a number of subsequent puffs. In one embodiment, steps 404 and after of Figure 3 are repeated nine times (i.e., for nine additional puffs). Optionally, there is a delay of about 30 seconds between each repetition of steps 404 and after. This repetition is intended to mimic a real-world usage session of the aerosol generation system 200.

[0277] The characteristics of the aerosol generated by a normally operating aerosol generating system (i.e., not defective) typically change for subsequent puffs. Figure 5 is a graph that depicts how the transmittance of the aerosol generated by a particular aerosol generating system changes for subsequent puffs. The y-axis 502 represents the transmittance, and the x-axis 504 represents the puff count. As the puff count progresses, the transmittance initially decreases and then increases again toward the end of the use session. The change in transmittance depends on the amount of aerosol generated for subsequent puffs and how the chemical composition of that aerosol changes. Different aerosol generating systems and different aerosol-forming substrates will have different patterns.

[0278] Figure 6 is a graph showing how the temperature of the aerosol generated by the aerosol generation system of Figure 5 changes with subsequent puffs. The y-axis 602 represents temperature and the x-axis 604 represents the number of puffs. The general trend for the aerosol temperature is to decrease as the number of puffs increases. This may be due to the heating profile employed by the aerosol generating device of the particular aerosol generation system. This may also result from changes in the chemistry of the aerosol-forming substrate as the substrate is depleted.

[0279] The pressure drop may follow a similar pattern as the temperature, with the pressure drop decreasing with increasing number of puffs.

[0280] To account for changes in the characteristics of the aerosol generated by a normally operating aerosol generating system for subsequent puffs, the method includes comparing the characteristics determined for the subsequent puff to different predetermined ranges of values. For example, the predetermined range of values ​​for transmittance follows a decreasing and then increasing pattern for subsequent puffs, similar to the trend shown in the graph of Figure 5. The predetermined range of values ​​for temperature and pressure drop follow a decreasing pattern similar to the trend shown in the graph of Figure 6.

[0281] The method further includes applying a purge airflow through the airflow channel to remove generated aerosols and other contaminants from the airflow channel that may affect future results. In some embodiments, the purge airflow is applied between each individual puff at the end of the predetermined time period of step 404 as described above. In other embodiments, the purge airflow is applied at the end of a use session (i.e., after 10 subsequent puffs have been performed). The step of applying the purge airflow includes applying the purge airflow for 28 seconds.

[0282] Applying the purge airflow includes configuring the test fixture 100 to a second configuration as shown in Figure 7. To do this, the controller of the test fixture 100 closes the first valve 112 and the third valve 130 and opens the second valve 116 and the fourth valve 134. If the valves are already in their respective closed or open states for the second configuration, the controller is configured to maintain the valves in that state. For example, if the first valve 112 is already closed, the controller maintains the first valve in its closed position.

[0283] The controller is also configured to turn on the second pump 136 to its blowing mode to draw air through the airflow channel in a second direction opposite to the first direction, such that air is drawn through the airflow channel 102 from the second junction 113 towards the first junction 108. The air flow is represented by dashed-dotted arrows in FIG.

[0284] Because the first valve 112 and the third valve 130 are closed, air cannot enter the airflow channel 102 through the first channel opening 105 or the third channel opening 124. Therefore, when the second pump 136 draws air in the second direction through the airflow channel 102, the air must be drawn into the airflow channel 102 through the fourth channel opening 128. The air drawn into the airflow channel 102 is fresh air that has passed through the airflow channel 102, including through the sensing assembly 118. This fresh air flushes out any aerosols or contaminants remaining in the airflow channel 102. Any remaining aerosols or contaminants are entrained in the airflow and transported out of the airflow channel 102 through the second channel opening 107.

[0285] Applying the purge airflow further includes configuring the test fixture 100 to a third configuration as shown in Figure 8. To do this, the controller of the test fixture 100 closes the first valve 112 and the third valve 130 and opens the second valve 116 and the fourth valve 134. Since the valves are already in their respective closed or open states for the third configuration when starting in the second configuration, the controller is configured to maintain the valves in that state. For example, the first valve 112 is already closed, so the controller maintains the first valve in its closed position.

[0286] The controller is also configured to turn on the second pump 136 into its suction mode to draw air in a first direction through the airflow channel 102, such that air is drawn through the airflow channel 102 from the first junction 108 towards the second junction 113. The air flow is represented by dashed lines in FIG.

[0287] Because the first valve 112 and the third valve 130 are closed, air cannot enter the airflow channel 102 through the first channel opening 105 or the third channel opening 124. Therefore, when the second pump 136 draws air in a first direction through the airflow channel 102, the air must be drawn into the airflow channel 102 through the second channel opening 107. The air drawn into the airflow channel 102 is fresh air that has passed through the airflow channel 102, including through the sensing assembly 118. This fresh air flushes out any aerosols or contaminants that have lingered within the airflow channel 102. Any lingering aerosols or contaminants are entrained in the airflow and transported out of the airflow channel 102 through the second channel opening 107.

[0288] In the embodiments described above, the purge airflow is applied in two different directions in two different configurations of the test fixture, hi some embodiments, applying only the purge airflow includes applying the airflow in a single direction and in a single configuration of the test fixture.

[0289] The test fixture 100 is described in combination with a first aerosol generation system 200 of the type that receives and electrically heats an aerosol-generating article that includes an aerosol-forming substrate. However, it will be appreciated that the test fixture 100, or similar test fixtures 100, can be used with other types of aerosol generation systems, provided that the aerosol generation system includes a mouthpiece through which a user of the system inhales in normal use of the aerosol generation system.

[0290] For example, in some embodiments, the aerosol generating system is of a type that includes an aerosol generating device and a cartridge that contains an aerosol-forming substrate. The aerosol generating device may be received in a cavity of the cartridge. Either the aerosol generating device or the cartridge includes a mouthpiece, and the mouthpiece is received in a mouthpiece receiving portion of the test fixture 100. The aerosol generating system is either activated by a user or is automatically activated in response to detecting a puff from the user. The aerosol generated by the aerosol generating device is then run in the same manner as described above.

[0291] In another embodiment, the aerosol generating system comprises an aerosol-generating article. The aerosol-generating article comprises a mouthpiece, an aerosol-forming substrate, and a combustible carbonaceous heat source. The mouthpiece of the article is received within the mouthpiece receiving portion of the first channel opening 105. The aerosol generating system is activated by igniting the combustible carbonaceous heat source. The aerosol generated by the aerosol generating device is then run off in the same manner as described above. Because the pump assembly 138 mimics a user's puff in the first configuration, the aerosol-generating article burns (and behaves) in the same manner as when used in a normal use session.

[0292] In embodiments in which the same test fixture 100 is used for different types of aerosol generation systems, the mouthpiece receiving portion of the first channel opening 105 is removable. In this manner, the mouthpiece receiving portion can be removed, as needed, and replaced with a mouthpiece receiving portion specifically configured for the aerosol generation system being analyzed.

[0293] A second embodiment of the test fixture 600 is shown in FIG. 9. The second embodiment test fixture 600 operates similarly to the first embodiment test fixture as shown in FIG. 1. Similar components are numbered accordingly. The second embodiment test fixture 600 differs in that it is suitable for testing more than one aerosol generation system 200 at a time. Thus, the test fixture 600 comprises two first channel openings 105, two first valves 112, two first branches 104 of the airflow channel, and two sensing assemblies 118. The airflow channel 102 and the above-mentioned components are positioned and configured such that a single pump assembly 138 is used to draw air through the airflow channel in both the first and second directions. The first valves are controlled in unison. Thus, in the first configuration of the test fixture 600, both first valves 112 are open and the single second valve 116 is closed. Thus, air drawn in a first direction by the first pump 132 draws aerosol generated by both aerosol generation systems into the airflow channel. As shown in Figure 9, the airflow channel 102 is configured such that aerosol from one of the aerosol generation systems is drawn past one of the sensing assemblies 118 and aerosol from the other of the aerosol generation systems is drawn past the other of the sensing assemblies 118. In this manner, aerosols generated by multiple aerosol generation systems can be analyzed separately and simultaneously.

[0294] Analysis of the generated aerosol characteristics is as described above with respect to test fixture 100.

[0295] In the second and third configurations of the test fixture 600, both first valves 112 are closed and the second valve 116 is open. Thus, purge air can be drawn through the airflow channel by the single pump assembly 138 in the same manner as described with respect to the test fixture 100. As shown in FIG. 9, the airflow channel 102 is configured so that the purge airflow passes through both sensor assemblies.

[0296] The test fixture 600 is designed for simultaneously testing two aerosol generation systems 200. However, it will be appreciated that the test fixture can be adapted to test any number of aerosol generation systems 200 following a similar manner to testing two aerosol generation systems 200 as shown in FIG.

[0297] A third embodiment of a test fixture 700 is shown in Figure 10. The third embodiment test fixture 700 operates similarly to the first embodiment test fixture as shown in Figure 1. Similar components are numbered accordingly.

[0298] The third embodiment of the test fixture 700 is another embodiment suitable for testing more than one aerosol generation system, specifically two aerosol generation systems at once. The test fixture 600 comprises two first channel openings 105 and two first branches 104 of the airflow channel. The test fixture 700 also comprises two second channel openings 107 and two second branches 106 of the airflow channel. Unlike the test fixture 600 of the second embodiment, the test fixture 700 of the third embodiment comprises a single sensor assembly 118.

[0299] The first branch 104 and the second branch 106 are connected to the sensor assembly through a rotary valve mechanism 702. The rotary valve mechanism 702 includes a single opening 704 formed in a rotating disk 706 that is rotatable by an electric motor of the rotary valve mechanism, not shown.

[0300] The rotary valve mechanism 702 further includes an airflow channel portion 708 for each of the first branch 104 and the second branch 106. Each airflow channel portion 708 is connected to a central column 710. An airflow channel portion 712 connects the central column 710 to the sensor assembly 118.

[0301] 10, the rotating disk 706 is positioned such that the single opening 704 is aligned with one of the first branches 104. In this manner, an aerosol generation system received in one of the first channel openings 105 can be tested by drawing the generated aerosol through the sensor assembly 118 using the pump assembly 138 as described with respect to the first embodiment. The generated aerosol will be drawn through the first branch 104, into the central column 710, and then through the airflow channel 712, then past the sensor assembly 118, and subsequently towards the pump assembly 138.

[0302] Because the rotating disk 706 only has a single opening 704, the other branches do not engage the sensor assembly when the disk is positioned as shown in Figure 10. In other words, in Figure 10, only one of the first channel openings is "open" and both second channel openings are "closed."

[0303] The rotating disk 706 can be controlled to be rotated by an electric motor to connect the different first or second branches (and associated first or second openings) to the sensor and pump assemblies.

[0304] 11 shows the rotating disk 706 in a second position with the single opening 704 aligned with one of the second branches 106 to connect one of the second channel openings to the sensor assembly 118 and pump assembly 138. In this position, a purge airflow can be applied through the sensor assembly as described with respect to the first embodiment.

[0305] During operation of the test fixture 700, the rotating disk 706 is rotated such that the single opening 704 sequentially engages each of the first and second branches to draw aerosol from each aerosol generation system past the sensor assembly and then perform a purge routine between drawing the aerosol from the aerosol generation system.

[0306] Unlike the second embodiment test fixture 600, the third embodiment test fixture 700 does not have the capability of simultaneous analysis of aerosols generated by multiple aerosol generation systems. Instead, the rotating disk 706 is rotated in stages.

[0307] Of course, the test fixture 700 may be configured to analyze more than two aerosol-generating systems, in which case additional first and second channel openings and associated features would be provided.

Claims

1. 1. A test fixture for analyzing an aerosol generated by an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, comprising: an airflow channel extending from the first channel opening configured to receive a mouthpiece of the aerosol generation system; a sensing assembly comprising: an emitter configured to emit electromagnetic radiation into the airflow channel; and a receiver configured to receive at least a portion of the electromagnetic radiation from the airflow channel; a pump assembly in a first configuration of the test fixture, the pump assembly being configured to draw air in a first direction through the airflow channel such that, in use, an aerosol generated by the aerosol generation system is drawn from the mouthpiece received within the first channel opening and through the airflow channel; a controller configured to determine at least one characteristic of the aerosol drawn through the airflow channel based on a signal received from the sensing assembly.

2. 2. The test setup of claim 1, wherein the controller is configured to compare the at least one determined characteristic to one or more predetermined values ​​for the or each characteristic, or to one or more predetermined ranges of values ​​for the or each characteristic.

3. 3. The testing facility of claim 2, wherein the controller is configured to determine that the aerosol generation system is faulty if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

4. A test setup according to any one of claims 1 to 3, wherein the first property of the aerosol determined by the controller relates to the transmittance of the aerosol.

5. The test fixture of any one of claims 1 to 4, wherein the sensing assembly further comprises a temperature sensor configured to measure a temperature of a portion of the airflow channel.

6. The test facility of claim 5 , wherein a second property of the aerosol determined by the controller is a temperature.

7. The test fixture of any preceding claim, wherein the sensing assembly further comprises a pressure sensor configured to measure pressure in a portion of the airflow channel.

8. 8. The test setup of claim 7, wherein a third characteristic determined by the controller is a pressure drop.

9. A test fixture according to any preceding claim, wherein the emitter comprises one or more LEDs.

10. 10. The test fixture of any one of claims 1 to 9, wherein in a second configuration of the test fixture, the pump assembly is configured to draw air through the airflow channel in a second direction opposite to the first direction.

11. The test fixture of claim 10 , further comprising a valve assembly.

12. 12. The test fixture of claim 11, wherein the valve assembly is configured such that when the test fixture is in the first configuration, the first channel opening is open and a second channel opening of the airflow channel is closed.

13. 13. The test fixture of claim 11 or 12, wherein the valve assembly is configured such that when the test fixture is in the second configuration, the first channel opening is closed and a second channel opening of the airflow channel is open.

14. A method for analysing an aerosol generated by an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, using a test setup according to any one of claims 1 to 13, comprising the steps of: positioning the mouthpiece of the aerosol generation system such that the mouthpiece is received within the first channel opening; drawing air in a first direction through the airflow channel using the pump assembly when the test fixture is in the first configuration, whereby an aerosol generated by the aerosol generation system is drawn from the mouthpiece received within the first channel opening and through the airflow channel; and determining at least one characteristic of the aerosol drawn through the airflow channel based on a signal received from the sensing assembly.

15. 1. A method for detecting a defect in an aerosol generating system comprising an aerosol-forming substrate and a mouthpiece, comprising: positioning a mouthpiece of the aerosol generating device such that the mouthpiece is received within a first channel opening of an airflow channel of a test fixture; using a pump assembly of the test fixture to draw air in a first direction through the airflow channel, whereby an aerosol generated by the aerosol generation system is drawn from the mouthpiece received within the first channel opening and through the airflow channel; determining at least one characteristic of the aerosol drawn through the airflow channel using a sensing assembly, the sensing assembly comprising an emitter configured to emit electromagnetic radiation into the airflow channel and a receiver configured to receive at least a portion of the electromagnetic radiation from the airflow channel; comparing the at least one determined characteristic to one or more predetermined values ​​for the or each characteristic or to one or more predetermined ranges of values ​​for the or each characteristic; and determining that the aerosol generation system is defective if at least one of the determined characteristics is not equal to one of the predetermined values ​​for that characteristic or does not fall within one of the predetermined ranges of values ​​for that characteristic.

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