A product monitoring device and infrared system

Abstract

This utility model discloses a product monitoring device and an infrared system, relating to the field of product condition monitoring technology. The product monitoring device includes a fiber Bragg grating sensor, which includes an optical fiber and at least one monitoring part arranged along the optical path of the optical fiber. The monitoring part is used to be attached to or embedded in the product to monitor at least one of the product's stress and temperature. The aforementioned product monitoring device, through the arrangement of the monitoring part attached to or embedded in the product, can meet the measurement requirements for the product's stress and temperature parameters. The measurement needs can be met using a single fiber Bragg grating sensor, saving space.

Description

Technical Field

[0001] This utility model relates to the field of product status monitoring technology, and more specifically, to a product monitoring device. Furthermore, this utility model also relates to an infrared system including the aforementioned product monitoring device. Background Technology

[0002] As infrared products continue to develop, performance requirements are becoming increasingly stringent, and the monitoring of internal components such as temperature rise and stress is becoming more and more rigorous.

[0003] In related technologies, temperature rise of products is monitored by adding temperature sensors, and stress of products is monitored by adding strain gauges. However, the monitoring components in this monitoring method require a large space, which is not conducive to the miniaturization design of infrared products.

[0004] In summary, how to reduce the space occupied by monitoring components is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a product monitoring device that can reduce the space occupied by monitoring components for monitoring product stress and temperature, which is beneficial to the miniaturization design of the product. Another purpose of this utility model is to provide an infrared system including the above-mentioned product monitoring device.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A product monitoring device, comprising:

[0008] A fiber optic grating sensor includes an optical fiber and at least one monitoring unit arranged along the optical path direction of the optical fiber. The monitoring unit is used to be attached to or embedded in a product to monitor at least one of the stress and temperature of the product.

[0009] Preferably, the optical fiber includes a first part and a second part, the first part having the monitoring unit, the second part being connected to the first part, and the second part being used to embed the product outside the area corresponding to the monitoring unit.

[0010] Preferably, the first part is provided with at least two intervals of the monitoring section, so as to correspond to two monitoring surfaces of at least one product or to the monitoring surfaces corresponding to at least two products respectively.

[0011] Preferably, the outer periphery of the monitoring unit is provided with a covering layer, which is used to at least cover the monitoring unit in order to protect the monitoring unit.

[0012] Preferably, the unfolded area S1 of the covering layer is greater than the area S2 of the outer peripheral surface of the monitoring unit.

[0013] Preferably, the coating layer is a thermally conductive element used to transfer temperature;

[0014] Alternatively, the covering layer may be an elastically deformable amplified component used to transfer stress.

[0015] Preferably, it further includes a demodulation component, which is signal-connected to the output end of the optical fiber and used to demodulate the monitoring information of the monitoring unit.

[0016] Preferably, the demodulation component includes a demodulator and a display, with one side of the demodulator connected to the output terminal and the other side of the demodulator connected to the display.

[0017] Preferably, the demodulator is provided with a transmission interface, which is used to connect to the output terminal through the signal output section of the product.

[0018] This utility model also provides an infrared system, including:

[0019] The product in question is an infrared product.

[0020] The product monitoring device is any one of the product monitoring devices described above, and the product monitoring device is used to monitor at least one of the stress and temperature of the product in real time.

[0021] The product monitoring device provided by this utility model includes a fiber Bragg grating sensor, wherein the fiber Bragg grating sensor includes an optical fiber and at least one monitoring part arranged along the optical path direction of the optical fiber. The monitoring part can be attached to the surface of the product or embedded in the product to meet the need to monitor at least one of the product's stress and temperature.

[0022] The beneficial effects of this utility model are as follows: by setting the monitoring part of the fiber optic grating sensor to be attached to the product surface or embedded in the product, the stress and temperature parameters of the product can be measured; specifically, by setting at least one monitoring part, the same fiber optic grating sensor can measure at least one parameter, saving space and facilitating the miniaturization design of the product. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 A schematic diagram of the product monitoring device provided by this utility model;

[0025] Figure 2 A schematic diagram illustrating an application of the product monitoring device provided by this utility model;

[0026] Figure 3 Another application diagram of the product monitoring device provided by this utility model;

[0027] Figure 4 This is a schematic diagram illustrating another application of the product monitoring device provided by this utility model.

[0028] Figure 5 This is a result display diagram of the demodulator provided by this utility model.

[0029] Figures 1-5 In the accompanying drawings, the reference numerals include:

[0030] 1-Sensor; 2-Demodulator; 3-Display; 4-Blade; 5-Detector; 6-Programmable Logic Element; 7-Lens; 8-Circuit Board; 9-Housing; 10-Signal Output Unit; 11-Monitoring Unit; 12-Fiber Optic Fiber; 13-Clad Layer; 14-Connector; 121-First Part; 122-Second Part. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] The core of this invention is to provide a product monitoring device that can simultaneously measure product stress and temperature parameters using a single fiber Bragg grating sensor, saving space. Another core aspect of this invention is to provide an infrared system that includes the aforementioned product monitoring device.

[0033] The product monitoring device provided by this utility model includes a fiber Bragg grating sensor 1 and a demodulation component. Please refer to the following for details. Figure 1 Specific products can be infrared products or other electronic products that require stress and temperature measurement. If the product is an infrared product, it can be a blade 4, a lens 7, a programmable logic element 6, a circuit board 8, a detector 5, etc.

[0034] The fiber Bragg grating sensor 1 includes an optical fiber 12 and at least one monitoring unit 11 arranged along the optical path of the optical fiber 12. The monitoring unit 11 at least covers the grating area, which needs to be aligned with the measurement point. The measurement point can be the entire surface or a partial surface of the product, depending on the actual measurement requirements. More specifically, the monitoring unit 11 is attached to or embedded in the product to monitor at least one of the product's stress and temperature.

[0035] In this embodiment, the optical fiber 12 and the monitoring unit 11 are connected by an optical signal. Specifically, when the optical signal is transmitted in the optical fiber 12, the monitoring unit 11 can selectively reflect or transmit light of a specific wavelength through the Bragg reflection principle, and then convert the reflected / transmitted light into an electrical signal and output it through a demodulation component.

[0036] At least one monitoring unit 11 arranged in the optical path direction of the optical fiber 12 can be used to monitor the temperature and stress of the same product, or to monitor the temperature and / or stress of different products.

[0037] If multiple monitoring units 11 are set up, based on the flexible optical path of the fiber optic grating sensor 1, the monitoring units 11 can be arranged according to the actual monitoring needs of one or more products, so as to be reliably applicable to product monitoring.

[0038] At least one monitoring unit 11 is provided in the optical path direction of the optical fiber 12, or two, three or more monitoring units 11 can be provided to monitor the parameters of multiple products or different parameters of the same product at the same time.

[0039] Specifically, if it is necessary to monitor the temperature or stress of two products simultaneously, two monitoring units 11 can be set in the optical path direction of the optical fiber 12. The monitoring information corresponding to the two monitoring units 11 can reflect the temperature or stress of the two products respectively.

[0040] If it is necessary to monitor the temperature or stress of two different surfaces of the same product, two monitoring units 11 can be set in the optical path direction of the optical fiber 12. The monitoring information corresponding to the two monitoring units 11 can reflect the temperature or stress of the two different surfaces of the same product respectively.

[0041] If it is necessary to monitor the temperature and stress of the same product, two monitoring units 11 can be set up in the optical path direction of the optical fiber 12, and the temperature information and stress information can be reflected by the two monitoring units 11 respectively.

[0042] If it is necessary to monitor the temperature of one product and the stress of the other, two monitoring units 11 can be set up through the optical path direction of the optical fiber 12. The monitoring information from the two monitoring units 11 can reflect the temperature and stress conditions.

[0043] By using the fiber optic grating sensor 1, the monitoring needs of different parameters of the same product can be met, as well as the monitoring needs of the same or different parameters of multiple products. The number and position of the monitoring unit 11 can be set according to the usage requirements. The monitoring unit 11 can be attached to or embedded in the product without the need for additional space, which can effectively save the space occupied by the sensor and facilitate the miniaturization design of the product assembly.

[0044] In this embodiment, the monitoring unit 11 is attached to or embedded in the product, and the design is tailored to the specific scenario. Before installing the monitoring unit 11, the surface of the product to which it will be attached or the groove to which it will be embedded needs to be cleaned to ensure reliable and accurate monitoring. Attachment can be achieved by applying adhesive to ensure reliable and stable monitoring.

[0045] Taking one specific implementation as an example, the monitoring of the local temperature of the shutter assembly (such as blades 4, lens 7) and housing 9 can be achieved by directly attaching the monitoring unit 11 to the surface, such as... Figure 2 This indicates that monitoring is performed by attachment. For the programmable logic element 6, the monitoring unit 11 can be placed at a location on the programmable logic element 6 with a larger radiation level, corresponding to the position of the housing 9. Alternatively, the monitoring unit 11 can be embedded within the programmable logic element 6, such as... Figure 3 The two monitoring units 11 of the demodulator 2, located relatively close to the right, correspond to two different methods of monitoring the state parameters of the programmable logic element 6. Real-time temperature monitoring ensures the reliability of the product.

[0046] Taking another specific implementation as an example, for electronic components such as detector 5 and circuit board 8, the monitoring part 11 can be attached to the surface to monitor stress; for shutter assemblies and connectors, the monitoring part 11 can be attached to the surface to monitor stress; specifically, for stress monitoring of connector 14, the monitoring part 11 can be attached to the outside of the female connector; for resonance between two structural components, the monitoring part 11 can be embedded in either structural component to monitor stress. Real-time monitoring of stress ensures the reliability of the product.

[0047] In this embodiment, the fiber optic grating sensor 1 has the characteristics of high sensitivity, small size, resistance to electromagnetic radiation, and flexible optical path for easy remote measurement. It eliminates the influence of light source power fluctuations and system losses, is suitable for long-term real-time monitoring, and can achieve multi-point distributed measurement by setting multiple monitoring units 11. It is well-suited for monitoring the temperature and stress of products.

[0048] Based on the above embodiments, the optical fiber 12 includes a first part 121 and a second part 122. The first part 121 is provided with a monitoring unit 11, and the second part 122 is connected to the first part 121 and is used to embed the product outside the area corresponding to the monitoring unit 11.

[0049] The first part 121 and the second part 122 of the optical fiber 12 can be a single segment or multiple segments spaced apart. If only a single segment monitoring unit 11 is required, then the area on the optical fiber 12 corresponding to the monitoring unit 11 is the first part 121, and the rest is the second part 122. The second part 122 can also be considered as the part that does not need to be installed in the product.

[0050] When in use, the area that the product needs to monitor is the first area. This first area is set in correspondence with the monitoring unit 11. The second part 122 of the optical fiber 12 can be embedded in other areas of the product other than the first area, so as to further save the space occupied by the sensor and facilitate the lightweight design of the product.

[0051] In one specific embodiment, the product is a circuit board 8 located inside the housing 9. The second part 122 of the optical fiber 12 can be embedded in the housing 9, and the first part 121 of the optical fiber 12 is arranged to form the monitoring unit 11, so as to minimize the space occupied by the sensor.

[0052] In one specific embodiment, the product is a housing 9. The monitoring part 11 arranged in the first part 121 of the optical fiber 12 is attached to any surface of the housing 9, while the second part 122 of the optical fiber 12 can be embedded in other surfaces to minimize the space occupied by the sensor.

[0053] Based on any of the above embodiments, the first part 121 is provided with at least two monitoring sections 11 spaced apart, so as to be able to correspond to two monitoring surfaces of at least one product or to monitoring surfaces corresponding to at least two products respectively.

[0054] In this embodiment, the first part 121 is provided with at least two monitoring units 11 spaced apart, and the area separated by the spaced-apartment configuration is a local area of ​​the second part 122.

[0055] By setting at least two monitoring sections 11, it is possible to monitor two monitoring surfaces of at least one product, or to monitor the monitoring surfaces corresponding to at least two products respectively.

[0056] In one specific embodiment, the first part 121 is provided with two monitoring units 11 spaced apart. The two monitoring units 11 are used to monitor the monitoring surfaces at two different locations of the same product, so as to enable real-time monitoring of stress or temperature at different locations of the same product.

[0057] In another specific embodiment, the first part 121 is provided with two monitoring units 11 spaced apart. The two monitoring units 11 are respectively used to monitor the two monitoring surfaces corresponding to the two products, so as to monitor the temperature / stress of the two products, or to monitor the temperature of one product and the stress of the other product.

[0058] In this embodiment, the spacing between the two monitoring units 11 that are spaced apart can be set according to the actual monitoring needs, and no further restrictions are imposed here.

[0059] Based on any of the above embodiments, please refer to Figure 1 The monitoring unit 11 is provided with a covering layer 13 on its outer periphery. The covering layer 13 is used to at least cover the monitoring unit 11 so as to protect the monitoring unit 11.

[0060] In this embodiment, the covering layer 13 can protect the monitoring unit 11, optimize the sensing performance, and ensure the reliability of stress or temperature monitoring.

[0061] The covering layer 13 can be formed by coating or by substrate encapsulation.

[0062] In one specific embodiment, the covering layer 13 is a substrate that can be bent and covered on the monitoring part 11, and the area of ​​the monitoring part 11 is covered according to the actual application.

[0063] In this embodiment, it should be noted that the number and location of the covering layers 13 correspond to the monitoring unit 11.

[0064] Based on any of the above embodiments, the unfolded area S1 of the covering layer 13 is greater than the area S2 of the outer peripheral surface of the monitoring unit 11.

[0065] In this embodiment, the covering layer 13 has an unfolded area, that is, the covering layer 13 can be bent or folded to form a space surrounding the monitoring part 11. The covering layer 13 can provide protection for the monitoring part 11 by reliably contacting the monitoring part 11.

[0066] The unfolded area S1 of the cladding layer 13 is greater than the area S2 of the outer peripheral surface of the monitoring part 11, that is, the cladding layer 13 can at least completely cover the outer peripheral surface of the monitoring part 11. Here, "at least" means that it can also cover the first part 121 area of ​​the monitoring part 11 corresponding to the optical fiber 12, so as to ensure a better protection effect.

[0067] Based on any of the above embodiments, the covering layer 13 is a thermally conductive element used to transfer temperature. In this case, for monitoring the product temperature, the thermally conductive element can protect the monitoring unit 11 and increase the thermal conductivity, making temperature monitoring more accurate. The thermally conductive element can be aluminum foil, which is easy to encapsulate and has a small size.

[0068] like Figure 2 and Figure 3 When specifically applied to product temperature monitoring (assuming the product is not subjected to external forces), the specific operating procedure is as follows:

[0069] Identify the heating and temperature measurement location that the product is concerned with, and attach or embed the monitoring unit 11 to the heating and temperature measurement location after it is covered by the covering layer 13; after the product starts to work and generates temperature, the output waveform of the fiber optic grating sensor 1 will change compared with the initial state. By comparing the amount of waveform shift before and after, the temperature change at the corresponding temperature measurement location of the product can be calculated.

[0070] The temperature measurement formula of fiber optic grating sensor 1 is mainly based on the temperature sensing principle of fiber optic grating, that is, temperature change will cause the center wavelength of fiber optic grating to drift.

[0071] The specific temperature measurement formula is as follows:

[0072] ;

[0073] In the formula, The center wavelength of the fiber grating after temperature change; The center wavelength of the fiber grating at the initial temperature. The temperature sensitivity coefficient of the fiber Bragg grating. This represents the change in temperature.

[0074] In another implementation, the covering layer 13 is an elastic deformation amplification component used to transmit stress. In this case, corresponding to product temperature monitoring, the elastic deformation amplification component can both protect the monitoring unit 11 and increase stress sensitivity, making stress monitoring more accurate. The covering layer 13 can be a plastic encapsulation material, which is easy to encapsulate and has a low cost.

[0075] like Figure 4 When applied to product stress, the specific operating procedure is as follows:

[0076] Identify the stress monitoring location that the product is concerned with, and set up the monitoring unit 11 according to the stress monitoring location. After the monitoring unit 11 is covered by the covering layer 13, it is attached to or embedded in the stress monitoring location. After the product is working, the grating peak position of the fiber optic grating sensor 1 will have a certain offset. By comparing the positions of the grating peaks before and after, the stress value of the corresponding stress monitoring location can be calculated.

[0077] The principle of stress measurement by fiber Bragg grating sensor 1 is mainly based on the Bragg reflection principle of fiber Bragg gratings and the elastic-optical effect of fiber Bragg gratings under stress. The following is a detailed explanation:

[0078] Fiber Bragg gratings are fabricated by forming periodic refractive index modulations in the fiber core. When broadband light propagates in fiber 12, light of a specific wavelength that satisfies the Bragg condition is reflected back, with the center wavelength of the reflected light being... Satisfying the formula:

[0079] ;

[0080] in Λ is the effective refractive index of fiber core 12, and Λ is the period of the grating.

[0081] When the fiber grating is subjected to stress, the fiber 12 will deform. This deformation will affect the grating period Λ and the effective refractive index of the fiber core. Changes occur. According to Hooke's Law, within the elastic limit, stress σ is directly proportional to strain ε, that is... Where E is the elastic modulus of the material; and the relative change in strain ε of the fiber grating with respect to the grating period Λ. and the effective refractive index of the fiber core relative change There is a certain relationship between them.

[0082] Taking into account both strain and elasto-optic effect of fiber Bragg gratings, the change in the center wavelength of the reflected light when the fiber Bragg grating is subjected to axial stress σ is... The relationship between the strain ε and the strain can be expressed as:

[0083] ;

[0084] Where p e This refers to the optical elasticity of fiber 12. It is determined by measuring the change in the center wavelength of the reflected light. Therefore, the stress σ acting on the fiber grating can be calculated based on the above formula.

[0085] By monitoring product stress in real time, the lifespan of the product corresponding to the stress monitoring location can be assessed based on the material's fatigue coefficient. For infrared products, assessing their lifespan can effectively prevent issues like image quality being affected by product lifespan limitations.

[0086] Based on any of the above embodiments, a demodulation component is also included. The demodulation component signal is connected to the output end of the optical fiber 12 and is used to demodulate the monitoring information of the monitoring unit 11.

[0087] In addition, the output end is also connected to a demodulation component. The signal connection here can be achieved through mechanical connectors, fusion splicing, etc. Fusion splicing refers to splicing the optical fiber at the output end of the sensor and the optical fiber at the input end of the demodulation component, which can reduce optical loss. Mechanical connectors use standard optical fiber interfaces to connect to the demodulation component, which can meet the requirements of quick plugging and unplugging.

[0088] By setting up the demodulation component, it is possible to demodulate the monitoring information of the monitoring unit 11 when the product generates a temperature rise or is subjected to external stress, so that the user can understand the temperature and stress status of the product in real time.

[0089] Based on any of the above embodiments, please refer to Figure 1 The demodulation component includes a demodulator 2 and a display 3. One side of the demodulator 2 is connected to the output terminal, and the other side of the demodulator 2 is connected to the display 3.

[0090] The demodulator 2 can demodulate the monitoring information from the monitoring unit 11, convert it into an electrical signal, and display it on the display 3 for real-time monitoring by the user. This monitoring method is simpler and more direct, requiring no upper-level computer operation for reading, thus enabling automatic real-time monitoring of the product's temperature or stress.

[0091] In this embodiment, the output end of the optical fiber 12 can be directly connected to the demodulator 2, or it can be connected to the demodulator 2 through an intermediate component. The intermediate component here is such as the output part of the mechanism assembly. The mechanism assembly here includes the infrared component with components such as the lens 7, blade 4, circuit board 8, and housing 9.

[0092] In one specific implementation, such as Figure 5 As shown, the line corresponding to O corresponds to the waveform of the internal grating of demodulator 2 (used for calibration); the line corresponding to A corresponds to the initial waveform when the product is not in operation; the peak value in this waveform corresponds to the value of the monitoring information from the two monitoring units before the product is not in operation, after being demodulated by demodulator 2; the line corresponding to B is the peak value of the initial waveform after the product is in operation, which causes the peak value to change to a new peak value; this new peak value corresponds to the value of the monitoring information from the two monitoring units after the product is in operation, after being demodulated by demodulator 2. Figure 5The significant change in peak values ​​before and after operation is clearly visible, and the temperature or stress of the product can be calculated based on this change using a calculation formula.

[0093] Based on any of the above embodiments, the demodulator 2 is provided with a transmission interface, which is used to connect to the output end through the product's signal output section 10.

[0094] Taking one specific embodiment as an example, the product is a core assembly including a blade assembly, a housing, and a circuit board. The signal output section 10 of the core assembly itself can be fused with the output end of the optical fiber 12. The signal output section 10 can output the image captured by the core assembly and the monitoring information monitored by the monitoring section 11 to the display screen so that they can be displayed simultaneously on the same display screen.

[0095] In addition to the aforementioned product monitoring device, this utility model also provides an infrared system including the product monitoring device disclosed in the above embodiments, which further includes infrared products. When the product monitoring device is applied to the field of real-time monitoring of the temperature and stress of infrared products, the overall volume of the infrared system can be effectively reduced. By maximizing the use of the space within the infrared system to place the fiber optic grating sensor 1, single-point / multi-point measurement of a single product or multi-point measurement of multiple products can be achieved. Real-time and reliable monitoring of product temperature and stress can be achieved without increasing power consumption, thus ensuring the operational reliability of the infrared system.

[0096] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0097] The product monitoring device and infrared system provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A product monitoring device, characterized in that, include: A fiber optic grating sensor (1) includes an optical fiber (12) and at least one monitoring unit (11) arranged along the optical path direction of the optical fiber (12). The monitoring unit (11) is used to attach to or embed in the product so as to monitor at least one of the stress and temperature of the product.

2. The product monitoring device of claim 1, wherein, The optical fiber (12) includes a first part (121) and a second part (122). The first part (121) is provided with the monitoring unit (11). The second part (122) is connected to the first part (121) and is used to embed the product outside the area corresponding to the monitoring unit (11).

3. The product monitoring device of claim 2, wherein, The first part (121) is provided with at least two intervals of the monitoring section (11) so as to be able to correspond to two monitoring surfaces of at least one product or to the monitoring surfaces corresponding to at least two products respectively.

4. The product monitoring device of claim 1, wherein, The monitoring unit (11) is provided with a covering layer (13) on its outer periphery. The covering layer (13) is used to at least cover the monitoring unit (11) so as to protect the monitoring unit (11).

5. The product monitoring device of claim 4, wherein, The unfolded area S1 of the covering layer (13) is greater than the area S2 of the outer peripheral surface of the monitoring part (11).

6. The product monitoring device of claim 5, wherein, The covering layer (13) is a thermally conductive element used to transfer temperature; Alternatively, the covering layer (13) is an elastic deformation amplification component used to transmit stress.

7. The product monitoring device of any one of claims 1 to 6, wherein, It also includes a demodulation component, which is connected to the output end of the optical fiber (12) and is used to demodulate the monitoring information of the monitoring unit (11).

8. The product monitoring device of claim 7, wherein, The demodulation component includes a demodulator (2) and a display (3). One side of the demodulator (2) is connected to the output terminal, and the other side of the demodulator (2) is connected to the display (3).

9. The product monitoring device of claim 8, wherein, The demodulator (2) is provided with a transmission interface, which is used to connect to the output terminal through the signal output section (10) of the product.

10. An infrared system characterized by, include: The product in question is an infrared product. The product monitoring device is the product monitoring device according to any one of claims 1 to 9, wherein the product monitoring device is used to monitor at least one of the stress and temperature of the product in real time.

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