An automatic calibration device for water activity of tobacco material and a method of using the same

Abstract

The application provides a kind of tobacco substance water activity automatic calibration device and its use method, belong to tobacco measurement technical field, this tobacco substance water activity automatic calibration device and method have measuring calibration equipment, control system, thermostatic mechanism, temperature sensor, humidity adjusting system, humidity sensor, constant pressure mechanism, air pressure sensor, communication system, weighing mechanism, slide, sample rotation mechanism, sample dish are provided in measuring calibration equipment, the use method of the equipment mainly includes: parameter setting stage, pre-equilibrium stage, skin weight stage, reference weighing stage, measurement stage, dynamic balance stage, cycle moisture absorption stage and calibration stage, can solve the current tobacco leaf water activity detection method has the problem of low automation level, cannot carry out multiple sample synchronous detection, environmental condition control is not comprehensive, operation is complicated, big error.

Description

Technical Field

[0001] The present invention belongs to the technical field of tobacco measurement, and in particular relates to an automatic calibration device for water activity of tobacco substances and a method for using the same. Background Art

[0002] Tobacco substances are extremely hygroscopic materials and are affected by the humidity of the surrounding air.

[0003] Water activity (also known as water activity, water activity, abbreviated as aw) refers to the ratio of the equilibrium vapor pressure of a certain type of tobacco to the saturated vapor pressure of pure water at the same temperature in a confined space.

[0004] If the water activity of tobacco materials is too high, water will be lost and the tobacco materials will shrink, which will seriously affect the production efficiency, process losses, and product quality of the processing process. It will also cause the finished cigarettes to be empty or the wrappers of the finished cigars to be broken. Therefore, each stage of cigar and cigarette production, storage, and transportation requires a specific water activity to maintain the moisture content. Therefore, tobacco water activity has always been an important indicator of concern and a key technical research direction in the tobacco industry. Under a specific temperature, pressure, and humidity environment, the water activity of the balanced tobacco material can be expressed as the ambient relative humidity (in decimal form). Therefore, this principle can be used to calibrate the water activity characteristics of tobacco materials.

[0005] At present, the calibration and measurement methods for the water activity of tobacco substances mostly use manual weighing and computer-assisted calculation. The automation level is low, and it is impossible to carry out simultaneous detection of multiple samples. The environmental conditions are not fully controlled, making it difficult for the previous system to reflect the water activity characteristics of tobacco substances. The operation is cumbersome and easily affected by external interference, resulting in large errors. It has the problems of low automation level, inability to carry out simultaneous detection of multiple samples, incomplete control of environmental conditions, cumbersome operation, and large errors. Summary of the Invention

[0006] In view of this, the present invention provides an automatic calibration device for the water activity of tobacco substances and a method for using the same, which can solve the problems of current tobacco leaf water activity detection methods, such as low automation level, inability to carry out simultaneous detection of multiple samples, incomplete control of environmental conditions, cumbersome operation, and large errors.

[0007] The present invention is achieved in that:

[0008] The first aspect of the present invention provides an automatic calibration device for the water activity of tobacco materials, comprising a measurement and calibration device, wherein the measurement and calibration device is provided with a control system, a constant temperature mechanism, a temperature sensor, a humidity adjustment system, a humidity sensor, a constant pressure mechanism, an air pressure sensor, a communication system, a weighing mechanism, a slide, a sample rotation mechanism, and a sample dish, wherein:

[0009] The measurement and calibration equipment has an environmental simulation cabin;

[0010] The control system is used to input and set parameters and drive the constant temperature mechanism, the temperature sensor, the humidity adjustment system, the humidity sensor, the constant pressure mechanism, and the air pressure sensor;

[0011] The constant temperature mechanism is used to adjust the temperature inside the environment simulation cabin;

[0012] The temperature sensor is used to monitor the temperature inside the environment simulation cabin in real time;

[0013] The humidity adjustment system is used to adjust the humidity inside the environment simulation cabin;

[0014] The humidity sensor is used to monitor the humidity inside the environment simulation cabin in real time;

[0015] The constant pressure mechanism is used to adjust the air pressure inside the environment simulation cabin;

[0016] The air pressure sensor is used to monitor the air pressure inside the environment simulation cabin in real time;

[0017] The communication system is used to feed back the measurement information to the control system;

[0018] The weighing mechanism is used to weigh the sample;

[0019] The slide is used to lift the sample onto the weighing mechanism;

[0020] The sample rotating mechanism is used to rotate the sample to be calibrated;

[0021] The sample dish is used to hold samples that need to be calibrated;

[0022] The control system is electrically connected to the communication system, the communication system is electrically connected to the constant temperature mechanism, the humidity adjustment system, the constant pressure mechanism, the weighing mechanism, the sample rotation mechanism, and the mobile cabin adjustment mechanism, the constant temperature mechanism is electrically connected to the temperature sensor, the humidity adjustment system is electrically connected to the humidity sensor, and the constant pressure mechanism is electrically connected to the air pressure sensor.

[0023] Based on the above technical solution, the automatic calibration device for water activity of tobacco substances of the present invention can also be improved as follows:

[0024] The sample rotation mechanism is a plum blossom-shaped rotating wheel fixed in the environmental simulation cabin, and an integrally formed sample dish holding ring is provided on the outside of the sample rotation mechanism. The number of the sample dish holding ring is a multiple of 3 + 1.

[0025] The fixed cabin and the movable cabin are controlled by a movable cabin regulating mechanism, and the movable cabin regulating mechanism drives the movable cabin to perform vertical movement in the fixed cabin.

[0026] The slide is a right-angled triangle structure, and the short right-angled side of the slide is arranged close to the weighing mechanism with a certain gap.

[0027] Wherein, the sample dish is a cup with a horizontal annular protrusion.

[0028] The environmental simulation cabin is enclosed by a fixed cabin and a movable cabin, and a sealed door is provided on the fixed cabin.

[0029] Furthermore, the outer wall of the fixed cabin is consistent in size with the inner wall of the movable cabin and is nested together. As the movable cabin adjustment structure is adjusted, the internal volume of the environmental simulation cabin is changed to achieve cabin pressure adjustment under sealed conditions.

[0030] A second aspect of the present invention provides a method for using an automatic calibration device for the water activity of tobacco materials. The steps of using the above-mentioned automatic calibration device for the water activity of tobacco materials include:

[0031] S1: Parameter setting stage: open the sealed door on the fixed cabin, place the empty sample dish into the ring of the sample rotating mechanism, set the atmospheric pressure constant value, temperature constant value, sample rotating mechanism rotation period and rotation interval period, pre-equilibrium period, dynamic equilibrium period on the control system; set the initial value and gradient value of humidity;

[0032] S2: Pre-balance stage: the sealed door is closed, the measurement and calibration equipment is started, the temperature sensor, the humidity sensor, and the air pressure sensor start working, and the measurement information is fed back to the control system through the communication system for driving the constant temperature mechanism, the humidity adjustment system, and the constant pressure mechanism until the air pressure constant value, the temperature constant value, and the humidity of the environmental simulation cabin are balanced to the initial value level, and then balanced according to the pre-balance cycle;

[0033] S3: Tare weight removal stage: the sample rotating mechanism rotates one circle in a step-by-step manner, pushing each sample dish into the weighing mechanism in sequence, and transmitting the weight to the control system via the communication system. The control system then tares each sample dish and marks each sample dish as zero weight.

[0034] S4: Reference weighing stage: the sealed door is opened, and the absolutely dry tobacco material is quickly placed into each of the sample dishes, leaving one sample dish empty for system calibration. The sealed door is quickly closed, and the sample rotating mechanism is rotated again in a step-by-step manner for one circle. The original weight of each sample is weighed and recorded;

[0035] S5: Measurement phase: After the baseline weighing is completed, the sample rotating mechanism cyclically weighs the weight of each sample dish according to the set rotation interval and transmits the weight to the control system through the communication system until the weight of the sample in the sample dish no longer increases due to moisture absorption. The control system determines that the sample has entered dynamic equilibrium and records the time it reaches equilibrium and the equilibrium weight.

[0036] S6: Dynamic equilibrium stage: When all the sample dishes have reached dynamic equilibrium, the measurement state of the sample is maintained until the set dynamic equilibrium period, completing the initial gradient moisture absorption test;

[0037] S7: cyclic moisture absorption stage: the control system directs the constant temperature mechanism, the humidity adjustment system, and the constant pressure mechanism to perform the cyclic automatic moisture absorption test of steps S5-S6 in ascending order according to the set gradient automatic humidity setting value until the tobacco material no longer absorbs moisture and increases in weight;

[0038] S8: Calibration stage: The control system calculates and outputs the moisture content C under each equilibrium state n，湿基 or C n，干基 and its corresponding relative humidity value, thereby completing the system calibration of the activity values ​​of tobacco substances with different moisture contents under the constant pressure and constant temperature conditions.

[0039] Furthermore, the sample rotation period in S10 is the number of samples × 6s, the rotation interval period is a multiple of the rotation period and is ≤10min, the pre-equilibrium period is 30min, and the dynamic equilibrium period is 8h; the initial value of the humidity is set to be greater than or equal to 10%RH; and the gradient value is less than or equal to 5%RH.

[0040] Furthermore, the calibration formula of S8 is:

[0041]

[0042]

[0043] Where C 干基，i，j The moisture content on a dry basis refers to the ratio of the mass of water in the wet material to the mass of the absolute dry material, where the mass of the dry material is equal to the mass of the material minus the mass of water. 湿基，i，jThe moisture content on a wet basis refers to the ratio of the mass of water in a wet material to the mass of the material, in %; M refers to weight, in g; "0" represents absolute dryness; i refers to the sample dish number, which can be a natural number such as 1, 2, 3, ..., n; j represents a point in a time series, which can be a natural number such as 1, 2, 3, ..., n.

[0044] Compared with the prior art, the automatic calibration device for the water activity of tobacco substances and the method for using the same provided by the present invention have the following beneficial effects: by providing a constant temperature mechanism, a temperature sensor, a humidity adjustment system, a humidity sensor, a constant pressure mechanism, and an air pressure sensor, comprehensive environmental control is achieved; the device can ensure the stability of atmospheric environmental parameters, minimize external interference, and avoid inaccurate measurements caused by excessive errors; by providing a sample rotation mechanism and a sample dish, multiple samples can be measured simultaneously, and sampling and placement are convenient; by providing a communication system, weighing data can be automatically output, and weighing accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1 A schematic diagram of the structure of an automatic calibration device for the water activity of tobacco materials;

[0047] Figure 2 A schematic diagram of a sample rotation mechanism for an automatic calibration device for the water activity of tobacco substances;

[0048] Figure 3 A schematic diagram of a sample dish for an automatic calibration device for water activity of tobacco substances;

[0049] Figure 4 A flow chart of a method for using an automatic calibration device for the water activity of tobacco materials;

[0050] Figure 5 An electrical connection diagram for an automatic calibration device for the water activity of tobacco substances;

[0051] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0052] 1. Control system; 11. Fixed cabin; 110. Sealed door; 12. Mobile cabin; 13. Mobile cabin adjustment mechanism; 14. Environmental simulation cabin; 2. Constant temperature mechanism; 21. Temperature sensor; 3. Humidity adjustment system; 31. Humidity sensor; 4. Constant pressure mechanism; 41. Air pressure sensor; 5. Communication system; 6. Thin film bag in simulation chamber; 7. Weighing mechanism; 8. Slide; 9. Sample rotation mechanism; 91. Sample dish. DETAILED DESCRIPTION

[0053] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0058] like Figure 1-3 and Figure 5 As shown, the first embodiment of the automatic calibration device for the water activity of tobacco substances provided by the first aspect of the present invention is provided. In this embodiment, a measurement and calibration device is provided, wherein the measurement and calibration device is provided with a control system 1, a constant temperature mechanism 2, a temperature sensor 21, a humidity adjustment system 3, a humidity sensor 31, a constant pressure mechanism 4, an air pressure sensor 41, a communication system 5, a weighing mechanism 7, a slide 8, a sample rotation mechanism 9, and a sample dish 91, wherein:

[0059] The measurement and calibration equipment has an environmental simulation cabin 14;

[0060] The control system 1 is used to input and set parameters and drive the constant temperature mechanism 2, the temperature sensor 21, the humidity adjustment system 3, the humidity sensor 31, the constant pressure mechanism 4, and the air pressure sensor 41;

[0061] The constant temperature mechanism 2 is used to adjust the temperature inside the environment simulation cabin 14;

[0062] The temperature sensor 21 is used to monitor the temperature inside the environment simulation cabin 14 in real time;

[0063] The humidity control system 3 is used to adjust the humidity inside the environment simulation cabin 14;

[0064] The humidity sensor 31 is used to monitor the humidity inside the environment simulation cabin 14 in real time;

[0065] The constant pressure mechanism 4 is used to adjust the air pressure inside the environment simulation cabin 14;

[0066] The air pressure sensor 41 is used to monitor the air pressure inside the environment simulation cabin 14 in real time;

[0067] The communication system 5 is used to feed back the measurement information to the control system 1;

[0068] The weighing mechanism 7 is used to weigh the weight of the sample;

[0069] The slide 8 is used to lift the sample onto the weighing mechanism 7;

[0070] The sample rotating mechanism 9 is used to rotate the sample to be calibrated;

[0071] The sample dish 91 is used to hold the sample that needs to be calibrated;

[0072] The control system 1 is electrically connected to the communication system 5, which is electrically connected to the constant temperature mechanism 2, the humidity adjustment system 3, the constant pressure mechanism 4, the weighing mechanism 7, the sample rotation mechanism 9, and the mobile cabin adjustment mechanism 13. The constant temperature mechanism 2 is electrically connected to the temperature sensor 21, the humidity adjustment system 3 is electrically connected to the humidity sensor 31, and the constant pressure mechanism 4 is electrically connected to the air pressure sensor 41. Among them, the temperature sensor 21 can be a temperature sensor with model LM35DZ LM35 produced by Shenzhen Weilide Technology Co., Ltd., the humidity sensor 31 can be a humidity sensor with model LIS2DETR produced by Shenzhen Xinchuangyang Technology Co., Ltd., and the air pressure sensor 41 can be a pressure sensor with model 209-008G produced by Shenzhen Huashengda Microelectronics Co., Ltd.

[0073] During use, the parameters are first input into the control system 1 so that the inside of the environmental simulation cabin 14 is balanced, and then the tobacco material is placed into the sample dish 91. The sample rotation mechanism 9 drives the sample dish 91 to perform stepping motion, and then the sample dish 91 is brought to the weighing mechanism 7 through the slide 8 for weighing, and the weighing data is output through the communication system 5.

[0074] Among them, in the above technical solution, the sample rotation mechanism 9 is a plum blossom-shaped rotating wheel fixed in the environmental simulation chamber 14, and an integrally formed sample dish holding ring is provided on the outside of the sample rotation mechanism 9, and the number of the sample dish holding ring is a multiple of 3 + 1.

[0075] The number of rings can be 4, 7, 10, etc.

[0076] Among them, in the above technical solution, the fixed cabin 11 and the movable cabin 12 are controlled by the movable cabin adjustment mechanism 13, and the movable cabin adjustment mechanism 13 drives the movable cabin 12 to perform vertical movement in the fixed cabin 11.

[0077] Among them, in the above technical solution, the slide 8 is a right-angled triangle structure, and the short right-angled side of the slide 8 is arranged next to the weighing mechanism 7, and the gap is not greater than 2 mm.

[0078] Among them, in the above technical solution, the sample dish 91 is a cup with a horizontal annular protrusion.

[0079] Among them, in the above technical solution, the environmental simulation cabin 14 is enclosed by a fixed cabin 11 and a movable cabin 12 , and a sealing door 110 is also provided on the fixed cabin 11 .

[0080] Furthermore, in the above technical solution, the outer wall of the fixed cabin 11 and the inner wall of the movable cabin 12 have the same size and are nested together, and the internal volume of the environmental simulation cabin 14 changes as the adjustment structure of the movable cabin 12 is adjusted.

[0081] like Figure 4FIG. 1 is a flow chart of a method for using an automatic calibration device for water activity of tobacco materials according to a second aspect of the present invention. In this method, the steps of using the automatic calibration device for water activity of tobacco materials include:

[0082] SI: Parameter setting stage: Open the sealed door 110 on the fixed cabin 11, place the empty sample dish 91 into the ring of the sample rotating mechanism 9, set the atmospheric pressure constant value, temperature constant value, sample rotating mechanism rotation period and rotation interval period, pre-equilibrium period, dynamic equilibrium period on the control system 1; set the initial value and gradient value of the humidity;

[0083] S2: Pre-balance stage: Close the sealed door 110, start the measurement and calibration equipment, and the temperature sensor 21, humidity sensor 31, and air pressure sensor 41 start working. The measurement information is fed back to the control system 1 through the communication system 5 to drive the constant temperature mechanism 2, humidity adjustment system 3, and constant pressure mechanism 4 until the constant pressure value, constant temperature value, and humidity of the environmental simulation chamber 14 are balanced to the initial value level, and then balanced according to the pre-balance cycle;

[0084] S3: Tare stage: The sample rotating mechanism 9 rotates one circle in a step-by-step manner, pushing each sample dish 91 into the weighing mechanism 7 in sequence, and the communication system 5 transmits the information to the control system 1; the control system 1 tares the weight of each sample dish 91 and marks each sample dish 91 as zero weight;

[0085] S4: Reference weighing stage: The sealed door 110 is opened, and the absolutely dry tobacco material is quickly placed into each sample dish 91, leaving one sample dish 91 empty for system calibration; the sealed door 110 is quickly closed, and the sample rotating mechanism 9 rotates one circle in a step-by-step manner again, and the original weight of each sample is weighed and recorded;

[0086] S5: Measurement phase: After the baseline weighing is completed, the sample rotating mechanism 9 cyclically weighs the weight of each sample dish 91 according to the set rotation interval and transmits the weight to the control system 1 through the communication system 5 until the weight of the sample in the sample dish 91 no longer increases due to moisture absorption. The control system 1 determines that the sample has entered dynamic equilibrium and records the time it reached equilibrium and the equilibrium weight.

[0087] S6: Dynamic equilibrium stage: When all sample dishes 91 reach dynamic equilibrium, the sample measurement state is maintained until the set dynamic equilibrium period, completing the initial gradient moisture absorption test;

[0088] S7: Cyclic moisture absorption stage: The control system 1 automatically adjusts the humidity to the set value according to the gradient, and instructs the constant temperature mechanism 2, the humidity adjustment system 3, and the constant pressure mechanism 4 to perform the cyclic automatic moisture absorption test of steps S5-S6 in ascending order until the tobacco material no longer absorbs moisture and increases in weight;

[0089] S8: Calibration stage: The control system 1 calculates and outputs the moisture content C under each equilibrium state n，湿基 or C n，干基 and its corresponding relative humidity value, thereby completing the system calibration of the activity values ​​of tobacco substances with different moisture contents under the constant pressure and constant temperature conditions.

[0090] Among them, the moisture content of the absolutely dry tobacco material is 0%, and the water activity C n =Relative humidity (expressed as a decimal).

[0091] Furthermore, in the above technical solution, the sample rotation period in S10 is the number of samples × 6s, the rotation interval period is a multiple of the rotation period and is ≤10min, the pre-balance period is 30min, and the dynamic balance period is 8h; the initial value of the humidity is set to be greater than or equal to 10%RH; and the gradient value is less than or equal to 5%RH.

[0092] Furthermore, in the above technical solution, the calibration formula of S8 is:

[0093]

[0094]

[0095] Where C 干基，ij The moisture content on a dry basis refers to the ratio of the mass of water in the wet material to the mass of the absolute dry material, where the mass of the dry material is equal to the mass of the material minus the mass of water. 湿基，ij The moisture content on a wet basis refers to the ratio of the mass of water in a wet material to the mass of the material, in %; M refers to weight, in g; "0" represents absolute dryness; i refers to the sample dish number, which can be a natural number such as 1, 2, 3, ..., n; j represents a point in a time series, which can be a natural number such as 1, 2, 3, ..., n.

[0096] Specifically, the principle of the present invention is: first, the parameters are input into the control system 1 so that the inside of the environmental simulation chamber 14 is balanced, and then the tobacco material is placed into the sample dish 91. The sample rotation mechanism 9 drives the sample dish 91 to perform stepping motion, and then the sample dish 91 is brought to the weighing mechanism 7 through the slide 8 for weighing, and the weighing data is output through the communication system 5.

[0097] Example 1: Water activity calibration values ​​of three parallel samples of three tobacco substances were collected under two ambient atmospheric conditions. The zero point of sample dish No. 10 was drifted by 0.001 g at a 60% RH gradient. Therefore, the weight of each sample at 60% RH was uniformly corrected by 0.001 g (M correction = M balance - 0.001), thereby finally obtaining the water activity calibration results of the three tobacco substance samples. The results are shown in Table 1:

[0098] Table 1. Water activity calibration results of three tobacco samples

[0099] The actual test environment: air pressure 101021Pa, temperature 34℃, relative humidity 52%RH

[0100]

[0101] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An automatic calibration device for the water activity of tobacco substances, comprising a measuring and calibration device, wherein the measuring and calibration device is provided with a control system, a constant temperature mechanism, a temperature sensor, a humidity adjustment system, a humidity sensor, a constant pressure mechanism, an air pressure sensor, a communication system, a weighing mechanism, a slide, a sample rotation mechanism, and a sample dish, wherein: The measurement and calibration equipment has an environmental simulation cabin; The control system is used to input and set parameters and drive the constant temperature mechanism, the temperature sensor, the humidity adjustment system, the humidity sensor, the constant pressure mechanism, and the air pressure sensor; The constant temperature mechanism is used to adjust the temperature inside the environment simulation cabin; The temperature sensor is used to monitor the temperature inside the environment simulation cabin in real time; The humidity adjustment system is used to adjust the humidity inside the environment simulation cabin; The humidity sensor is used to monitor the humidity inside the environment simulation cabin in real time; The constant pressure mechanism is used to adjust the air pressure inside the environment simulation cabin; The air pressure sensor is used to monitor the air pressure inside the environment simulation cabin in real time; The communication system is used to feed back the measurement information to the control system; The weighing mechanism is used to weigh the sample; The slide is used to lift the sample onto the weighing mechanism; The sample rotating mechanism is used to rotate the sample to be calibrated; The sample dish is used to hold samples that need to be calibrated; The control system is electrically connected to the communication system, the communication system is electrically connected to the constant temperature mechanism, the humidity adjustment system, the constant pressure mechanism, the weighing mechanism, the sample rotation mechanism, and the mobile cabin adjustment mechanism, the constant temperature mechanism is electrically connected to the temperature sensor, the humidity adjustment system is electrically connected to the humidity sensor, and the constant pressure mechanism is electrically connected to the air pressure sensor; The environmental simulation cabin is enclosed by a fixed cabin and a movable cabin, and the fixed cabin is also provided with a sealed door; the fixed cabin and the movable cabin are controlled by a movable cabin adjustment mechanism, and the movable cabin adjustment mechanism drives the movable cabin to perform vertical movement in the fixed cabin.

2. The automatic calibration device for water activity of tobacco materials according to claim 1, characterized in that: The sample rotating mechanism is a plum blossom-shaped rotating wheel fixed in the environmental simulation cabin. An integrally formed sample dish containing ring is provided on the outside of the sample rotating mechanism. The number of the sample dish containing ring is a multiple of 3+1.

3. The automatic calibration device for water activity of tobacco material according to claim 2, characterized in that: The slideway is a right-angled triangle structure, and the short right-angled side of the slideway is arranged close to the weighing mechanism with a certain gap.

4. The automatic calibration device for water activity of tobacco materials according to claim 3, characterized in that: The sample dish is a cup with a horizontal annular protrusion.

5. The automatic calibration device for water activity of tobacco material according to claim 4, characterized in that: The outer wall of the fixed cabin is consistent in size with the inner wall of the movable cabin and is nested together. As the movable cabin adjustment structure is adjusted, the internal volume of the environmental simulation cabin is changed to achieve cabin pressure adjustment under sealed conditions.

6. A method for using an automatic calibration device for water activity of tobacco materials, using the automatic calibration device for water activity of tobacco materials according to claim 5, comprising: S1: Parameter setting stage: open the sealed door on the fixed cabin, place the empty sample dish into the ring of the sample rotating mechanism, set the atmospheric pressure constant value, temperature constant value, sample rotating mechanism rotation period and rotation interval period, pre-equilibrium period, dynamic equilibrium period on the control system; set the initial value and gradient value of humidity; S2: Pre-balance stage: the sealed door is closed, the measurement and calibration equipment is started, the temperature sensor, the humidity sensor, and the air pressure sensor start working, and the measurement information is fed back to the control system through the communication system for driving the constant temperature mechanism, the humidity adjustment system, and the constant pressure mechanism until the air pressure constant value, the temperature constant value, and the humidity of the environmental simulation cabin are balanced to the initial value level, and then balanced according to the pre-balance cycle; S3: Tare weight removal stage: the sample rotating mechanism rotates one circle in a step-by-step manner, pushing each sample dish into the weighing mechanism in sequence, and transmitting the weight to the control system via the communication system. The control system then tares each sample dish and marks each sample dish as zero weight. S4: Reference weighing stage: the sealed door is opened, and the absolutely dry tobacco material is quickly placed into each of the sample dishes, leaving one sample dish empty for system calibration. The sealed door is quickly closed, and the sample rotating mechanism is rotated again in a step-by-step manner for one circle. The original weight of each sample is weighed and recorded; S5: Measurement phase: After the baseline weighing is completed, the sample rotating mechanism cyclically weighs the weight of each sample dish according to the set rotation interval and transmits the weight to the control system through the communication system until the weight of the sample in the sample dish no longer increases due to moisture absorption. The control system determines that the sample has entered dynamic equilibrium and records the time it reaches equilibrium and the equilibrium weight. S6: Dynamic equilibrium stage: When all the sample dishes have reached dynamic equilibrium, the measurement state of the sample is maintained until the set dynamic equilibrium period, completing the initial gradient moisture absorption test; S7: cyclic moisture absorption stage: the control system directs the constant temperature mechanism, the humidity adjustment system, and the constant pressure mechanism to perform the cyclic automatic moisture absorption test of steps S5-S6 in ascending order according to the set gradient automatic humidity setting value until the tobacco material no longer absorbs moisture and increases in weight; S8: Calibration stage: The control system calculates and outputs the moisture content C under each equilibrium state n,湿基 or C n,干基 and its corresponding relative humidity value, thereby completing the system calibration of the activity values ​​of tobacco substances with different moisture contents under the constant pressure and constant temperature conditions.

7. The method for using the automatic calibration device for water activity of tobacco materials according to claim 6, characterized in that: in, The sample rotation period in S1 is the number of samples × 6 s, the rotation interval period is a multiple of the rotation period and is ≤10 min, the pre-equilibrium period is 30 min, and the dynamic equilibrium period is 8 h; the initial value of the humidity is set to be greater than or equal to 10% RH; and the gradient value is less than or equal to 5% RH.

8. The method for using the automatic calibration device for water activity of tobacco materials according to claim 7, characterized in that: in, The calibration formula for S8 is: ； ； Where, C 干基,i,j The moisture content on a dry basis refers to the ratio of the mass of water in the wet material to the mass of the absolute dry material, where the mass of the dry material is equal to the mass of the material minus the mass of water. 湿基,i,j The moisture content on a wet basis refers to the ratio of the mass of water in a wet material to the mass of the material, in units of %; M refers to the weight, in units of g; "0" represents absolute dryness; i refers to the sample dish number, which is a natural number such as 1, 2, 3, ..., n; j represents a point in the time series, which is a natural number such as 1, 2, 3, ..., n.

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