Complex dielectric constant measuring device and measuring method

Abstract

The invention discloses a complex dielectric constant measuring device, which comprises a clamp (1), a first measuring plate (2), a second measuring plate (3) and an impedance analyzer (4), and is characterized in that the clamp (1) is used for controlling the distance between the first measuring plate (2) and the second measuring plate (3); and the first measuring plate (2) and the second measuring plate (3) are electrically connected with the impedance analyzer (4) respectively. The invention also provides a method for measuring by using the complex dielectric constant measuring device. By using the complex dielectric constant measuring device provided by the invention, the complex dielectric constant of the aerosol generating matrix section of the heated cigarette product can be accurately measured, the aerosol generating matrix section of the heated cigarette product does not need to be subjected to sample preparation treatment such as tabletting, and various original physical and chemical parameters of the heated cigarette product are not changed; the detection result is more in line with the actual smoking performance of the heating cigarette product, and can adapt to the measurement requirements of heating cigarette products with different sizes.

Description

Technical Field

[0001] The present application relates to the technical field of detection equipment, and in particular to a complex dielectric constant measurement device and a measurement method. Background Art

[0002] In recent years, new tobacco products represented by heated cigarettes have rapidly emerged around the world as a healthier and more contemporary innovative product, attracting more and more consumers. As an alternative to traditional tobacco, heated cigarettes have been sought after by many consumers for their diverse structures and lower harm.

[0003] When a heated cigarette product is inhaled, the heating device provides heat to make the aerosol generating matrix segment in the heated cigarette product generate aerosol for inhalation. The two complement each other and jointly affect the consumer's consumption experience and use safety. The complex dielectric constant of the aerosol generating matrix segment is closely related to its loss under high-frequency electromagnetic fields. Measuring its complex dielectric constant can well guide the development of aerosol generating matrix products under the action of high-frequency heating devices. Based on physical and chemical parameters such as density, porosity, moisture content, ingredient list, and strength, existing equipment cannot effectively and accurately measure the complex dielectric constant of the aerosol generating matrix segment. Summary of the invention

[0004] In order to solve the above technical problems, the first purpose of the present invention is to provide a complex dielectric constant measuring device; the second purpose of the present invention is to provide a method for measuring using the above complex dielectric constant measuring device; using the complex dielectric constant measuring device provided by the present application, the complex dielectric constant of the aerosol generating matrix segment of the heated cigarette product can be accurately measured, and there is no need to perform sample preparation processing such as pressing the aerosol generating matrix segment of the heated cigarette product, and the original physical and chemical parameters of the heated cigarette product will not be changed. The detected results are more in line with the performance of the heated cigarette product during actual smoking, and can adapt to the measurement needs of heated cigarette products of different sizes.

[0005] The technical solution provided by the present invention is as follows: A complex dielectric constant measuring device comprises: a fixture, a first measuring plate, a second measuring plate and an impedance analyzer. The fixture is used to control the distance between the first measurement plate and the second measurement plate; The first measuring board and the second measuring board are electrically connected to the impedance analyzer respectively.

[0006] Preferably, the fixture comprises a first slider, a second slider and a base. The first slider and the second slider are slidably disposed on the base, respectively, and the sliding tracks of the first slider and the second slider overlap; The first measuring plate is fixedly connected to the first sliding block, and the second measuring plate is fixedly connected to the second sliding block.

[0007] Preferably, the base is further provided with a screw having a first thread segment and a second thread segment with opposite rotation directions; the first slider is threadedly matched with the first thread segment, and the second slider is threadedly matched with the second thread segment.

[0008] Preferably, the screw has a handle extending out of the base; and / or, The base is also provided with a guide rod, and the first sliding block and the second sliding block are slidably matched with the guide rod.

[0009] Preferably, the fixture also includes two adapter blocks, the adapter blocks have a first connecting surface and a second connecting surface that are perpendicular to each other, the first connecting surface is fixedly connected to the top surface of the first slider or the second slider, the second connecting surface is fixedly connected to the first measuring plate or the second measuring plate, and the second connecting surfaces of the two adapter blocks are opposite.

[0010] Preferably, the base has a scale, and the scale is parallel to the sliding tracks of the first slider and the second slider.

[0011] Preferably, the first measuring board is provided with a measuring electrode, a first terminal and a guarding electrode, and the second measuring board is provided with a guarded electrode and a second terminal; The first terminal and the second terminal are electrically connected to the impedance analyzer through cables respectively; The guard electrode is annular and arranged at the periphery of the measuring electrode, and an insulating area is formed between the guard electrode and the measuring electrode; The protected electrode and the measuring electrode are arranged opposite to each other, and the diameter of the protected electrode is larger than the diameter of the measuring electrode; the diameter of the measuring electrode is smaller than the diameter of the sample to be tested.

[0012] Preferably, the width of the insulating region is 0.1-2 mm; and / or, The cable is a coaxial cable.

[0013] The method for measuring using any of the complex dielectric constant measuring devices described above comprises the following steps: S1. Adjust the impedance analyzer to the test frequency, and use a fixture to adjust the distance between the first measuring plate and the second measuring plate to be equal to the length of the sample to be tested; S2. Place the sample to be tested between the first measuring plate and the second measuring plate, and measure the series capacitance With parallel capacitor ; S3. Rotate the sample to be tested 90° around the axis and measure the series capacitance. With parallel capacitor ; S4. Calculate the complex dielectric constant of the sample to be tested ; S5. Complex dielectric constants of multiple samples to be tested , calculate the average complex dielectric constant .

[0014] Preferably, before step S1, the following steps are also included: S0, cutting the aerosol generating matrix segment of the heated cigarette product into a cylinder, and the relationship between the height h and the diameter D of the cylinder is ≤h≤ , i.e. the sample to be tested; and / or, Step S1 also includes the step of using a standard copper pillar to determine the distance between the first measurement board and the second measurement board.

[0015] The present application first provides a complex dielectric constant measuring device, including: a fixture, a first measuring plate, a second measuring plate and an impedance analyzer, the fixture is used to control the spacing between the first measuring plate and the second measuring plate; the first measuring plate and the second measuring plate are electrically connected to the impedance analyzer respectively, and a measuring circuit is formed when the two ends of the sample to be tested are connected to the first measuring plate and the second measuring plate respectively, and the measurement data can be obtained through the impedance analyzer. Using the complex dielectric constant measuring device provided by the present application, the complex dielectric constant of the aerosol generating matrix section of the heated cigarette product can be accurately measured, and there is no need to perform sample preparation processing such as pressing the aerosol generating matrix section of the heated cigarette product, and the original physical and chemical parameters (density, porosity, moisture content, ingredient list, strength, etc.) of the heated cigarette product will not be changed. The detected results are more in line with the performance of the heated cigarette product during actual smoking; and for heated cigarette products of different sizes, the device provided by the present application can change the spacing between the first measuring plate and the second measuring plate, so as to adapt to the detection needs of samples of different lengths, corresponding to the detection needs of heated cigarette products of different sizes, and can effectively and accurately measure the complex dielectric constant of the heated cigarette product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 Schematic diagram of the structure of a complex dielectric constant measuring device in an embodiment of the present invention; Figure 2 is a schematic structural diagram of a first measurement board in an embodiment of the present invention; Figure 3 is a schematic structural diagram of a second measurement board in an embodiment of the present invention; Figure 4 This is a summary diagram of the test results of series and parallel capacitors in Example 1 of the present invention; Figure numerals: 1-clamp; 11-first slider; 12-second slider; 13-base; 14-screw; 141-handle; 15-guide rod; 16-adapter block; 2-first measuring plate; 21-measuring electrode; 22-first terminal; 23-protective electrode; 24-insulating area; 3-second measuring plate; 31-protected electrode; 32-second terminal; 4-impedance analyzer; 5-cable. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0020] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 a limitation on the present application.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0022] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0023] As shown in the figure, an embodiment of the present invention provides a complex dielectric constant measuring device, including: a fixture 1, a first measuring plate 2, a second measuring plate 3 and an impedance analyzer 4, The fixture 1 is used to control the distance between the first measuring plate 2 and the second measuring plate 3; The first measuring board 2 and the second measuring board 3 are electrically connected to the impedance analyzer 4 respectively.

[0024] The present application first provides a complex dielectric constant measuring device, including: a fixture 1, a first measuring plate 2, a second measuring plate 3 and an impedance analyzer 4, wherein the fixture 1 is used to control the distance between the first measuring plate 2 and the second measuring plate 3; the first measuring plate 2 and the second measuring plate 3 are electrically connected to the impedance analyzer 4 respectively, and a measurement loop is formed when the two ends of the sample to be tested are connected to the first measuring plate 2 and the second measuring plate 3 respectively, and measurement data can be obtained through the impedance analyzer 4. By using the complex dielectric constant measuring device provided in the present application, the complex dielectric constant of the aerosol generating matrix segment of the heated cigarette product can be accurately measured. There is no need to perform sample preparation processing such as tableting on the aerosol generating matrix segment of the heated cigarette product, and the original physical and chemical parameters (density, porosity, moisture content, ingredient list, strength, etc.) of the heated cigarette product will not be changed. The test results are more in line with the performance of the heated cigarette product during actual smoking; and, for heated cigarette products of different sizes, the device provided in the present application can change the spacing between the first measuring plate 2 and the second measuring plate 3, so as to adapt to the testing needs of samples of different lengths, and can effectively and accurately measure the complex dielectric constant of the heated cigarette product in accordance with the testing needs of heated cigarette products of different sizes.

[0025] The impedance analyzer 4 used in the present application may be a commercially available instrument.

[0026] Preferably, the fixture 1 comprises a first slider 11, a second slider 12 and a base 13. The first slider 11 and the second slider 12 are slidably disposed on the base 13, respectively, and the sliding tracks of the first slider 11 and the second slider 12 overlap; The first measuring plate 2 is fixedly connected to the first sliding block 11 , and the second measuring plate 3 is fixedly connected to the second sliding block 12 .

[0027] Preferably, the fixture 1 includes a first slider 11, a second slider 12 and a base 13. The first slider 11 and the second slider 12 are respectively slidably arranged on the base 13, and the sliding tracks of the first slider 11 and the second slider 12 overlap. The first measuring plate 2 is fixedly connected to the first slider 11, and the second measuring plate 3 is fixedly connected to the second slider 12. The two sliders are used to adjust the distance between the first measuring plate 2 and the second measuring plate 3, and the sliding tracks of the first slider 11 and the second slider 12 overlap, which can ensure that the relative positions of the first measuring plate 2 and the second measuring plate 3 do not deviate during the movement, and maintain good centering.

[0028] Preferably, the base 13 is further provided with a screw 14, which has a first thread segment and a second thread segment with opposite rotation directions; the first slider 11 is threadedly matched with the first thread segment, and the second slider 12 is threadedly matched with the second thread segment.

[0029] The stability of the distance between the first measuring plate 2 and the second measuring plate 3 can be achieved by setting a higher sliding resistance between the first slider 11 and the second slider 12 and the base 13. That is, when the external force is insufficient to overcome the sliding resistance, the first slider 11 and the second slider 12 keep their positions unchanged, so that the distance between the first measuring plate 2 and the second measuring plate 3 respectively fixedly connected to the sliders remains unchanged; when it needs to be changed, the operator can apply external force to move the sliders.

[0030] More preferably, the movement and spacing of the first slider 11 and the second slider 12 are adjusted simultaneously by the screw 14. By providing the first thread segment and the second thread segment with opposite rotation directions on the screw 14, and making the first slider 11 and the second slider 12 threadably matched with the first thread segment and the second thread segment respectively, when the screw 14 rotates in one direction, due to the different rotation directions of the thread segments, the first slider 11 and the second slider 12 will translate in different directions, approaching or moving away from each other, so that by switching the rotation direction of the screw 14, the spacing of the first slider 11 and the second slider 12 can be adjusted.

[0031] The first thread segment and the second thread segment may respectively occupy half the length of the screw rod 14 , so that the distances that the two sliders can move are the same.

[0032] Preferably, the screw rod 14 has a handle 141 extending out of the base 13; and / or, The base 13 is further provided with a guide rod 15 , and the first sliding block 11 and the second sliding block 12 are slidably matched with the guide rod 15 .

[0033] Preferably, the screw rod 14 has a handle 141 extending out of the base 13, so that the operator can hold it and rotate it.

[0034] Preferably, the base 13 is also provided with a guide rod 15, and the first slider 11 and the second slider 12 are slidably matched with the guide rod 15. The guiding and limiting function of the guide rod 15 is utilized to ensure the accuracy of the sliding direction of the first slider 11 and the second slider 12, thereby ensuring that the first measuring plate 2 and the second measuring plate 3 maintain good centering.

[0035] Preferably, the fixture 1 also includes two adapter blocks 16, the adapter blocks 16 have a first connecting surface and a second connecting surface that are perpendicular to each other, the first connecting surface is fixedly connected to the top surface of the first slider 11 or the second slider 12, the second connecting surface is fixedly connected to the first measuring plate 2 or the second measuring plate 3, and the second connecting surfaces of the two adapter blocks 16 are opposite to each other.

[0036] Preferably, the first slider 11 and the second slider 12 are respectively provided with an adapter block 16, and the adapter block 16 has a first connecting surface and a second connecting surface that are perpendicular to each other. The first connecting surface is fixedly connected to the top surface of the slider and is in a horizontal state, and the second connecting surface is in a vertical state. The second connecting surfaces of the two adapter blocks 16 are opposite to each other, so that the first measuring plate 2 and the second measuring plate 3 are installed by using two upright and opposite second connecting surfaces, and the first measuring plate 2 and the second measuring plate 3 are kept in a vertical state and arranged relatively to each other, so that the sample to be tested is clamped between the first measuring plate 2 and the second measuring plate 3 for measurement.

[0037] Preferably, the base 13 has a scale, and the scale is parallel to the sliding tracks of the first slider 11 and the second slider 12 .

[0038] More preferably, the seat 13 has a scale, and the scale is parallel to the sliding tracks of the first slider 11 and the second slider 12, that is, parallel to the sliding tracks of the first measuring plate 2 and the second measuring plate 3. Then, during the measurement process, the distance between the first measuring plate 2 and the second measuring plate 3 can be accurately determined by the scale, so as to avoid squeezing the sample during the measurement process, resulting in the measurement result not accurately reflecting the true performance of the sample.

[0039] The positions of the first slider 11 and the second slider 12 (or the positions of the first measuring plate 2 and the second measuring plate 3) are read on the scale respectively, and in subsequent measurements, the positions of the first slider 11 and the second slider 12 are kept corresponding to the recorded readings, so that the spacing between the first measuring plate 2 and the second measuring plate 3 can be kept stable. It is preferred to set a pointer on the first measuring plate 2 and the second measuring plate 3, or to set a pointer on the first slider 11 and the second slider 12 for easy reading.

[0040] Preferably, the first measuring board 2 is provided with a measuring electrode 21, a first terminal 22 and a guarding electrode 23, and the second measuring board 3 is provided with a guarded electrode 31 and a second terminal 32; The first terminal 22 and the second terminal 32 are electrically connected to the impedance analyzer 4 through the cable 5 respectively; The protection electrode 23 is annular and is disposed on the outer periphery of the measuring electrode 21 , and an insulating region 24 is formed between the protection electrode 23 and the measuring electrode 21 ; The protected electrode 31 is arranged opposite to the measuring electrode 21 , and the diameter of the protected electrode 31 is larger than the diameter of the measuring electrode 21 ; the diameter of the measuring electrode 21 is smaller than the diameter of the sample to be tested.

[0041] Preferably, the first measuring plate 2 is provided with a measuring electrode 21, a first terminal 22 and a guarding electrode 23, and the second measuring plate 3 is provided with a guarded electrode 31 and a second terminal 32; the first terminal 22 and the second terminal 32 are electrically connected to the impedance analyzer 4 through the cable 5 respectively; the guarding electrode 23 is annular and is arranged at the periphery of the measuring electrode 21, and there is an insulating area 24 between the guarding electrode 23 and the measuring electrode 21; the guarded electrode 31 is arranged opposite to the measuring electrode 21, and the diameter of the guarded electrode 31 is larger than the diameter of the measuring electrode 21; the diameter of the measuring electrode 21 is smaller than the diameter of the sample to be tested. The sample to be tested is sandwiched between the first measuring plate 2 and the second measuring plate 3, and one end contacts the guarding electrode 23 and the measuring electrode 21, and the other end contacts the guarded electrode 31, thereby forming a loop with the impedance analyzer 4 to achieve measurement. The present application stipulates that the diameter of the measuring electrode 21 is smaller than the diameter of the sample to be tested, and when one end of the sample to be tested contacts the measuring electrode 21, it will completely cover the measuring electrode 21; the present application also stipulates that the protected electrode 31 is arranged opposite to the measuring electrode 21, and the diameter of the protected electrode 31 is larger than the diameter of the measuring electrode 21. If the two measuring plates are fitted together, the measuring electrode 21 will be completely covered by the protected electrode 31. When measuring, when the other end of the sample to be tested contacts the protected electrode 31, all the current in the overlapping part of the sample to be tested and the measuring electrode 21 (that is, the area of ​​the measuring electrode 21) will pass through the sample to be tested and enter the protected electrode 31 to form a loop, thereby obtaining an accurate measurement result.

[0042] For aerosol generating products of different diameters, if the diameter of the sample to be tested is much smaller than the electrode, the edge capacitance will account for a relatively large proportion, affecting the measurement accuracy. Therefore, as long as the diameter of the sample to be tested is larger than the diameter of the measuring electrode, and the material to be tested is evenly distributed, it is applicable to the measuring device of the present application. Specifically, the diameter of the sample to be tested ≥ the diameter of the measuring electrode minus 1 mm is applicable. The present application limits the diameter of the measuring electrode 21 to be smaller than the diameter of the sample to be tested, which can ensure the accuracy of the detection results of the sample to be tested; by setting the electrode size to be smaller than the smallest diameter of the multiple samples to be measured, it can be ensured that all diameters of the samples to be tested can be detected using the device of the present application.

[0043] More preferably, the outer diameter of the protective electrode 23 is smaller than or equal to the diameter of the sample to be tested, and the diameter of the measuring electrode 21 located inside the protective electrode 23 must be smaller than the diameter of the sample to be tested.

[0044] The protection electrode 23 is provided to form a three-electrode system with the measuring electrode 21 and the protected electrode 22, which can reduce the interference of external factors on the measurement and reduce the probability of error. In the present application, the measuring electrode 21 can be a positive electrode, and the protected electrode 31 corresponds to a negative electrode; the measuring electrode 21 can also be a negative electrode, and the protected electrode corresponds to a positive electrode.

[0045] Preferably, the width of the insulating region 24 is 0.1-2 mm; and / or, The cable 5 is a coaxial cable.

[0046] Preferably, the width of the insulating area 24 is 0.1-2 mm, so that there is a gap of 0.1-2 mm between the measuring electrode 21 and the protective electrode 23 , which can not only play a protective role, but also allow the sample to be tested to contact the measuring electrode 21 and the protective electrode 23 at the same time.

[0047] Preferably, the cable 5 is a coaxial cable, which has no radiation loss and is almost not interfered by external signals. When connecting, it is necessary to prevent the cable 5 from being tangled to avoid fluctuations in the measured data.

[0048] The method for measuring using any of the complex dielectric constant measuring devices described above comprises the following steps: S1. Adjust the impedance analyzer 4 to the test frequency, and use the fixture 1 to adjust the distance between the first measuring plate 2 and the second measuring plate 3 to be equal to the length of the sample to be tested; S2. Place the sample to be tested between the first measuring plate 2 and the second measuring plate 3 to measure the series capacitance. With parallel capacitor ; S3. Rotate the sample to be tested 90° around the axis and measure the series capacitance. With parallel capacitor ; S4. Calculate the complex dielectric constant of the sample to be tested ; S5. Complex dielectric constants of multiple samples to be tested , calculate the average complex dielectric constant .

[0049] The present application also provides a method for measuring using any of the complex dielectric constant measuring devices described above. First, preheat and adjust the impedance analyzer 4 to the test frequency (for example: 13.56MHz), and adjust the distance between the first measuring plate 2 and the second measuring plate 3 (there is no order requirement between these two steps, and either one can be performed first), and prepare for the test. Then, place the sample to be tested between the first measuring plate 2 and the second measuring plate 3 and contact the positive electrode 21, the protective electrode 22 and the negative electrode 31, and measure to obtain the series capacitance of the first measurement. With parallel capacitor ; Then rotate the sample to be tested 90° around the axis to obtain the second measured series capacitance With parallel capacitor , through the series capacitor With parallel capacitor , Series Capacitor With parallel capacitor , the complex dielectric constants measured on both sides can be calculated separately , and then use the complex dielectric constants of multiple samples to be tested , calculate the average complex dielectric constant .

[0050] For cylindrical specimens, it is recommended to rotate the specimen 90° axially before testing again to reduce the measurement error caused by deformation.

[0051] Complex dielectric constant The measurement formula is well known in the art and is calculated according to Formula I: Formula I In Formula I: —The distance between the positive and negative electrodes of the test electrode, in millimeters (mm); — shunt capacitance, in femtofarads (fF); —The area facing the test electrode, in millimeters (mm); —vacuum dielectric constant, 8.854187817 fF / mm; —Series capacitance, measured in femtofarads (fF).

[0052] Average complex permittivity Calculate according to formula II. Calculate the average complex dielectric constant By removing extreme values ​​and then taking the average, and taking this average as the final result, the error can be reduced.

[0053] Formula II In Formula II: —The average complex dielectric constant after depolarization, a dimensionless quantity.

[0054] —Any complex dielectric constant of any sample, a dimensionless quantity.

[0055] —The maximum value of the complex dielectric constant obtained during the test, a dimensionless quantity.

[0056] —The minimum value of the complex dielectric constant obtained during the test, a dimensionless quantity.

[0057] Preferably, before step S1, the following steps are also included: S0, cutting the aerosol generating matrix segment of the heated cigarette product into a cylinder, and the relationship between the height h and the diameter D of the cylinder is ≤h≤ , i.e. the sample to be tested; and / or, Step S1 also includes a step of using a standard copper column to determine the distance between the first measurement board 2 and the second measurement board 3 .

[0058] According to the requirement of GB / T 31838 that the height h of the cylindrical sample should be smaller than the diameter D, the aerosol generating matrix segment is cut to obtain a cylinder. The relationship between the height h and the diameter D of the cylinder is: ≤h≤ , to reduce the edge capacitance and thus reduce the measurement error.

[0059] In addition, the test sample is required to be intact in appearance. During the test, the impedance analyzer 4 is stable without abnormal movement. After the test data is stable, it is maintained for ≥10s before recording the data.

[0060] Preferably, the method further includes the step of using a standard copper column to determine the distance between the first measurement board 2 and the second measurement board 3 , wherein the height of the standard copper column is the same as that of the sample to be tested.

[0061] Example 1 A complex dielectric constant measuring device comprises: a fixture 1, a first measuring plate 2, a second measuring plate 3 and an impedance analyzer 4, The clamp 1 includes a first slider 11, a second slider 12, a base 13, a screw 14 and a guide rod 15. The screw 14 has a first thread segment and a second thread segment with opposite rotation directions. The first slider 11 is threadedly matched with the first thread segment, the second slider 12 is threadedly matched with the second thread segment, and the first slider 11 and the second slider 12 are slidably matched with the guide rod 15. The screw 14 has a handle 141 extending out of the base 13. The fixture 1 further includes two adapter blocks 16, each of which has a first connecting surface and a second connecting surface that are perpendicular to each other. The first connecting surface of one adapter block 16 is fixedly connected to the top surface of the first slider 11, and the second connecting surface is fixedly connected to the first measuring plate 2. The first connecting surface of the other adapter block 16 is fixedly connected to the top surface of the second slider 12, and the second connecting surface is fixedly connected to the second measuring plate 3. The second connecting surfaces of the two adapter blocks 16 are opposite to each other. The base 13 has scales, and the scales are parallel to the sliding tracks of the first slider 11 and the second slider 12; The first measuring plate 2 is provided with a measuring electrode 21, a first terminal 22 and a guarding electrode 23, and the second measuring plate 3 is provided with a guarded electrode 31 and a second terminal 32; the guarding electrode 23 is annular and is arranged at the outer periphery of the measuring electrode 21, and an insulating area 24 is formed between the guarding electrode 23 and the measuring electrode 21, and the width of the insulating area 24 is 1 mm; The first terminal 22 and the second terminal 32 are electrically connected to the impedance analyzer 4 through the cable 5 , respectively. The cable 5 is a coaxial cable.

[0062] The outer diameter of the protection electrode 23 is the same as the outer diameter of the protected electrode 31 , and the diameter of the protection electrode 23 is equal to the diameter of the sample to be tested.

[0063] Using the complex dielectric constant measurement device described above, perform the measurement according to the following steps: S0, the diameter of the aerosol generating section of a certain heated cigarette product is D = 7mm, and the sample height h is required to be ≤h≤ In the experiment, the aerosol generating matrix segment was cut short to prepare two specifications of 3mm and 5mm, and 5 test samples of each specification were prepared for experimental testing; S1. Preheat, calibrate, and adjust the impedance analyzer 4 to the test frequency (13.56 MHz); Use a standard copper column with the same length as the sample to be tested, clamp the standard copper column with tweezers and place it at the test position, adjust and determine the distance between the first measuring plate 2 and the second measuring plate 3 until the standard copper column is clamped, and record the scale data at this time; S2. Replace the standard copper column as the test sample, place it between the first measuring plate 2 and the second measuring plate 3, and adjust the scale to be the same as the recorded scale data; measure and record the series capacitance With parallel capacitor ; S3. Use tweezers to hold the sample to be tested, rotate it 90° around the axis, and then put it back to the test position. Measure and record the series capacitance. With parallel capacitor ; S4. Calculate the two complex dielectric constants of the sample to be tested according to formula I ; S5. Prepare 5 samples of each specification in turn and use the measured complex dielectric constant , calculate the average complex dielectric constant according to formula II .

[0064] The aerosol generating section of a certain heated cigarette product was cut into 3mm and 5mm samples to prepare the test series and parallel capacitors. The results are summarized as follows: Figure 4 The positive and negative electrode facing area A, the positive and negative electrode spacing d, as well as the average series capacitance, average parallel capacitance, and average complex dielectric constant are shown in Table 1.

[0065] Table 1

[0066] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A complex dielectric constant measuring device, characterized in that: include: A fixture (1), a first measurement board (2), a second measurement board (3) and an impedance analyzer (4), The fixture (1) is used to control the distance between the first measuring plate (2) and the second measuring plate (3); The first measuring board (2) and the second measuring board (3) are electrically connected to an impedance analyzer (4) respectively.

2. The complex dielectric constant measuring device according to claim 1, characterized in that: The clamp (1) comprises a first slider (11), a second slider (12) and a base (13). The first sliding block (11) and the second sliding block (12) are respectively slidably disposed on the base (13), and the sliding tracks of the first sliding block (11) and the second sliding block (12) overlap; The first measuring plate (2) is fixedly connected to the first sliding block (11), and the second measuring plate (3) is fixedly connected to the second sliding block (12).

3. The complex dielectric constant measuring device according to claim 2, characterized in that: The base (13) is further provided with a screw rod (14), the screw rod (14) having a first thread segment and a second thread segment with opposite rotation directions; the first slider (11) is threadedly matched with the first thread segment, and the second slider (12) is threadedly matched with the second thread segment.

4. The complex dielectric constant measuring device according to claim 3, characterized in that: The screw rod (14) has a handle (141) extending out of the base (13); and / or, The base (13) is further provided with a guide rod (15), and the first sliding block (11) and the second sliding block (12) are slidably matched with the guide rod (15).

5. The complex dielectric constant measuring device according to claim 2, characterized in that: The clamp (1) further comprises two adapter blocks (16), the adapter blocks (16) having a first connecting surface and a second connecting surface which are perpendicular to each other, the first connecting surface being fixedly connected to the top surface of the first slider (11) or the second slider (12), the second connecting surface being fixedly connected to the first measuring plate (2) or the second measuring plate (3), and the second connecting surfaces of the two adapter blocks (16) being opposite to each other.

6. The complex dielectric constant measuring device according to any one of claims 2 to 5, characterized in that: The base (13) has a scale, and the scale is parallel to the sliding tracks of the first sliding block (11) and the second sliding block (12).

7. The complex dielectric constant measuring device according to claim 1, characterized in that: The first measuring plate (2) is provided with a measuring electrode (21), a first terminal (22) and a guarding electrode (23), and the second measuring plate (3) is provided with a guarded electrode (31) and a second terminal (32); The first terminal (22) and the second terminal (32) are electrically connected to the impedance analyzer (4) via a cable (5) respectively; The protective electrode (23) is annular and is disposed on the outer periphery of the measuring electrode (21), and an insulating region (24) is formed between the protective electrode (23) and the measuring electrode (21); The protected electrode (31) and the measuring electrode (21) are arranged opposite to each other, and the diameter of the protected electrode (31) is larger than the diameter of the measuring electrode (21); the diameter of the measuring electrode (21) is smaller than the diameter of the sample to be tested.

8. The complex dielectric constant measuring device according to claim 7, characterized in that: The width of the insulating region (24) is 0.1-2 mm; and / or, The cable (5) is a coaxial cable.

9. A method for measuring using the complex dielectric constant measuring device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Adjust the impedance analyzer (4) to the test frequency, and use the fixture (1) to adjust the distance between the first measuring plate (2) and the second measuring plate (3) to be equal to the length of the sample to be tested; S2. Place the sample to be tested between the first measuring plate (2) and the second measuring plate (3) to measure the series capacitance. With parallel capacitor ; S3. Rotate the sample to be tested 90° around the axis and measure the series capacitance. With parallel capacitor ; S4. Calculate the complex dielectric constant of the sample to be tested ; S5. Complex dielectric constants of multiple samples to be tested , calculate the average complex dielectric constant .

10. The method according to claim 9, characterized in that The following steps are also included before step S1: S0, cutting the aerosol generating matrix segment of the heated cigarette product into a cylinder, and the relationship between the height h and the diameter D of the cylinder is: ≤h≤ , i.e. the sample to be tested; and / or, Step S1 also includes the step of using a standard copper column to determine the distance between the first measurement plate (2) and the second measurement plate (3).

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