A temperature measuring device

Abstract

This disclosure provides a temperature measuring device, comprising a housing, a stacked dual-detector assembly, a beam splitter module, a calibration plate, and an optical lens sequentially stacked on the housing along the optical path. The device also includes an environmental sensor assembly and a signal processing circuit. The calibration plate is rotatably disposed in the optical path between the optical lens and the beam splitter module, and has a high emissivity region, a low emissivity region, and a light-avoiding region on its surface. The calibration plate is driven to rotate by a connected rotary motor to selectively insert the high emissivity region, the low emissivity region, or the light-avoiding region into the optical path, thereby switching between a working mode and a calibration mode. The signal processing circuit is electrically connected to the stacked dual-detector assembly and the environmental sensor assembly, respectively, and calculates and outputs the temperature value using a built-in dynamic wavelength ratio correction algorithm. This effectively improves the temperature measuring accuracy of the device.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of temperature measurement technology, specifically relating to a temperature measuring device. Background Technology

[0002] Infrared thermometry, with its core advantages of non-contact measurement, fast response, and wide measurement range, has been widely applied in various technical fields such as industrial automation, power line inspection, medical diagnosis, and cold chain logistics. Among these, dual-wavelength infrared thermometry calculates temperature by extracting the ratio of infrared radiation signals from two different wavelength channels. This effectively reduces the impact of emissivity fluctuations of the target object on the measurement results. Compared to single-wavelength infrared thermometry, it offers higher measurement accuracy and environmental adaptability, and has become the mainstream technical solution for high-precision temperature measurement scenarios.

[0003] However, existing dual-wavelength infrared temperature measurement devices still suffer from several technical challenges in practical applications, making it difficult to meet the demands for high-precision, high-stability, and high-efficiency temperature measurement. Firstly, the parallel layout of dual detectors often results in a complex optical path system structure, making it prone to central axis misalignment of the two wavelength channels, thus affecting the matching accuracy of the dual signals and directly reducing the accuracy of the temperature measurement results. Secondly, the calibration process requires external standard temperature sources or offline calibration by disassembling the device, which is cumbersome and time-consuming, making on-site calibration impossible and severely impacting the continuity and efficiency of measurement work. Thirdly, environmental factors such as changes in temperature and humidity, and suspended dust particles can affect the accuracy of the measurement. The transmission process of infrared radiation generates attenuation interference, and existing devices lack an effective dynamic environmental compensation mechanism, resulting in a significant decrease in temperature measurement accuracy in complex environments. Fourth, the operating temperature stability of the detector directly determines its noise level and signal detection accuracy. The temperature control structure of existing devices mostly adopts passive heat dissipation or simple active cooling schemes, which makes it difficult to achieve high-precision closed-loop temperature control and cannot ensure that the detector is always in the optimal operating temperature range. Fifth, in dusty industrial environments, cold chain frosting environments, or environments with strong electromagnetic interference, optical lenses are easily contaminated with pollutants or affected by environmental interference, which not only attenuates the received intensity of infrared signals but also interferes with the accuracy of the calibration process. Existing devices lack targeted protection designs. Summary of the Invention

[0004] The embodiments disclosed herein are intended to at least address one of the technical problems existing in the prior art, and to provide a temperature measuring device.

[0005] Embodiments of this disclosure provide a temperature measuring device, the temperature measuring device comprising: case; An optical lens for receiving infrared light radiated by a target object; A beam splitting module is located on the rear optical path of the optical lens and is used to separate incident infrared light into a first wavelength channel and a second wavelength channel. A calibration plate is rotatably disposed in the optical path between the optical lens and the beam splitter module. The plate has a high emissivity region, a low emissivity region, and a light-avoiding region. The calibration plate is driven to rotate by a rotary motor connected to it, so as to selectively cut the high emissivity region, the low emissivity region, or the light-avoiding region into the optical path, thereby realizing the switching between the working mode and the calibration mode. A stacked dual detector assembly includes a first detector and a second detector stacked along the optical path direction, which are respectively used to receive optical signals from the first wavelength channel and the second wavelength channel and convert them into a first electrical signal. An environmental sensor assembly is disposed in the housing. The environmental sensor assembly includes a temperature and humidity sensor and a particulate matter concentration sensor, which are used to collect environmental temperature and humidity and particulate matter concentration parameters and convert them into a second electrical signal, respectively. The signal processing circuit is electrically connected to the stacked dual detector assembly and the environmental sensor assembly, respectively, and is used to receive the first electrical signal and the second electrical signal, and calculate and output the temperature value through the built-in dynamic wavelength ratio correction algorithm. The stacked dual detector assembly, beam splitter module, calibration plate, and optical lens are sequentially stacked on the housing along the optical path direction.

[0006] Optionally, the temperature measuring device further includes a heat-insulated temperature control module; The thermal insulation temperature control module includes a thermal insulation substrate and a thermoelectric cooling chip embedded inside the thermal insulation substrate; one side of the thermal insulation substrate is fixedly connected to the housing, and the other side is used to support the stacked dual detector assembly.

[0007] Optionally, the stacked dual detector assembly further includes an insulating substrate; The first detector and the second detector are respectively fabricated on the front and back sides of the insulating substrate by photolithography integration process, and their photosensitive central axes are collinear and coincident; the photosensitive surface of the first detector is covered with a bandpass filter adapted to the wavelength of the first wavelength channel, and the photosensitive surface of the second detector is covered with a bandpass filter adapted to the wavelength of the second wavelength channel.

[0008] Optionally, the cold end of the thermoelectric cooling chip is thermally connected to the insulating substrate, and its hot end is fixedly connected to the heat dissipation fins.

[0009] Optionally, the cooling temperature of the thermoelectric cooler is controlled in a closed loop by a detector noise feedback circuit. The input terminal of the detector noise feedback circuit is electrically connected to the stacked dual detector assembly, and its output terminal is electrically connected to the control terminal of the thermoelectric cooler.

[0010] Optionally, the wavelength range of the first wavelength channel is 1.4μm–1.6μm, and the wavelength range of the second wavelength channel is 1.8μm–2.0μm.

[0011] Optionally, the high emissivity region is a structure formed by spraying a silicon carbide coating onto the surface of a copper substrate, with an infrared emissivity greater than 0.95; the low emissivity region is a structure formed by polishing the surface of an aluminum substrate, with an infrared emissivity less than 0.1; and the light-blocking region is a through-hole structure. The calibration plate is provided with multiple positioning grooves spaced circumferentially along its edge. The positioning grooves cooperate with the Hall sensor on the rotary motor to achieve precise positioning of the rotation angle.

[0012] Optionally, the signal processing circuit has a wavelength-attenuation relationship matrix pre-stored inside; The execution of the dynamic wavelength ratio correction algorithm includes: based on the received first and second electrical signals, calculating the dynamic compensation coefficient through the wavelength-attenuation relationship matrix, and correcting the ratio of the dual-wavelength electrical signals output by the stacked dual detector assembly to obtain the actual temperature value.

[0013] Optionally, the temperature measuring device further includes at least one air curtain nozzle disposed on the housing; The air curtain nozzle is connected to an inert gas source and is used to spray an inert gas curtain onto the optical path in front of the optical lens during calibration mode or temperature measurement in harsh environments, so as to isolate the interference of environmental dust on the optical path.

[0014] The temperature measuring device of the present disclosure can achieve precise optical path matching, in-situ rapid calibration, dynamic environmental compensation and stable temperature control of the detector, thereby improving the temperature measuring accuracy and working efficiency of the temperature measuring device. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a temperature measuring device according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a calibration plate according to another embodiment of the present disclosure; Figure 3 This is a schematic diagram of the assembly structure of a heat-insulating substrate and a thermoelectric cooling chip according to another embodiment of the present disclosure. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figures 1 to 3 As shown, a temperature measuring device 100 includes a housing 110, an optical lens 120, a beam splitter module 130, a calibration plate 140, a stacked dual detector assembly 150, an environmental sensor assembly 160, and a signal processing circuit 170. The optical lens 120 receives infrared light radiated by a target object. The beam splitter module 130 is located on the rear optical path of the optical lens 120 and is used to separate the incident infrared light into a first wavelength channel and a second wavelength channel. The calibration plate 140 is rotatably disposed on the optical path between the optical lens 120 and the beam splitter module 130, and its plate body is provided with a high emissivity region 141, a low emissivity region 142, and a light-avoiding region 143. Furthermore, the calibration plate 140 is driven to rotate by a connected rotary motor 200 to selectively insert the high emissivity region 141, the low emissivity region 142, or the light-avoiding region 143 into the optical path, thereby achieving switching between the operating mode and the calibration mode.

[0018] The stacked dual detector assembly 150 includes a first detector 151 and a second detector 152 stacked along the optical path direction. These detectors are used to receive optical signals from the first wavelength channel and the second wavelength channel, respectively, and convert them into a first electrical signal. The environmental sensor assembly 160 is disposed on the housing 110. The environmental sensor assembly 160 includes a temperature and humidity sensor and a particulate matter concentration sensor. These sensors are used to collect environmental temperature, humidity, and particulate matter concentration parameters, respectively, and convert them into a second electrical signal. The signal processing circuit 170 is electrically connected to both the stacked dual detector assembly 150 and the environmental sensor assembly 160. It receives the first and second electrical signals and calculates and outputs a temperature value using a built-in dynamic wavelength ratio correction algorithm. The stacked dual detector assembly 150, the beam splitter module 130, the calibration plate 140, and the optical lens 120 are sequentially stacked on the housing 110 along the optical path direction.

[0019] For example, such as Figure 1 and Figure 3 As shown, the temperature measuring device 100 also includes a heat insulation temperature control module 180. The heat insulation temperature control module 180 includes a heat insulation substrate 181 and a thermoelectric cooling chip 182 embedded inside the heat insulation substrate 181. One side of the heat insulation substrate 181 is fixedly connected to the housing 110, and the other side is used to support the stacked dual detector assembly 150.

[0020] Furthermore, the stacked dual detector assembly 150 also includes an insulating substrate 153. The first detector 151 and the second detector 152 are respectively fabricated on the front and back sides of the insulating substrate 153 using a photolithography integration process, and their photosensitive central axes are collinear and coincident. The photosensitive surface of the first detector 151 is covered with a bandpass filter adapted to the wavelength of the first wavelength channel, and the photosensitive surface of the second detector 152 is covered with a bandpass filter adapted to the wavelength of the second wavelength channel.

[0021] Furthermore, the cold end 1821 of the thermoelectric cooling chip 182 is thermally connected to the insulating substrate 153, and its hot end is fixedly connected to the heat dissipation fins 1822.

[0022] The cooling temperature of the thermoelectric cooler 182 is controlled in a closed loop by a detector noise feedback circuit (not shown). The input terminal of the detector noise feedback circuit is electrically connected to the stacked dual detector assembly 150, and its output terminal is electrically connected to the control terminal of the thermoelectric cooler 182.

[0023] For example, the wavelength range of the first wavelength channel is 1.4μm–1.6μm, and the wavelength range of the second wavelength channel is 1.8μm–2.0μm.

[0024] For example, such as Figure 1 and Figure 2 As shown, the high emissivity region 141 is a structure formed by spraying a silicon carbide coating onto the surface of a copper substrate, with an infrared emissivity greater than 0.95. The low emissivity region 142 is a structure formed by polishing the surface of an aluminum substrate, with an infrared emissivity less than 0.1. The light-blocking region 143 is a through-hole structure. The calibration plate 140 has multiple positioning grooves 143 spaced circumferentially along its edge. The positioning grooves 143 cooperate with the Hall sensor on the rotary motor 200 to achieve precise positioning of the rotation angle.

[0025] For example, the signal processing circuit 170 internally stores a wavelength-attenuation relationship matrix. The execution of the dynamic wavelength ratio correction algorithm includes: calculating a dynamic compensation coefficient based on the received first and second electrical signals through the wavelength-attenuation relationship matrix, and correcting the ratio of the dual-wavelength electrical signals output by the stacked dual detector assembly 150 to obtain the actual temperature value.

[0026] For example, such as Figure 1 As shown, the temperature measuring device 100 also includes at least one air curtain nozzle 190 disposed on the housing 110. The air curtain nozzle 190 is connected to an inert gas source and is used to spray an inert gas curtain into the optical path in front of the optical lens 120 during temperature measurement in calibration mode or harsh environment, so as to isolate the interference of environmental dust on the optical path.

[0027] The temperature measuring device of the present disclosure has the following beneficial effects: By employing photolithography to integrate two detectors onto the front and back of the same insulating substrate, forming a coaxial stacked layout with collinear central axes, the optical path misalignment problem inherent in traditional parallel layouts is effectively solved. This ensures precise matching of the dual-wavelength channel optical signals and significantly improves temperature measurement accuracy. Simultaneously, this stacked structure drastically reduces the size of the detector components, increases the device's integration density, and facilitates installation and deployment in confined spaces.

[0028] The rotatable calibration plate allows for rapid switching between high and low emissivity zones, and combined with the precise positioning of the Hall sensor, in-situ calibration can be completed without disassembling the device, effectively avoiding the impact of traditional offline calibration methods on the continuity of measurement work. The high and low emissivity zones utilize coatings and substrates with excellent stability to ensure the reliability of the calibration reference, significantly improving calibration accuracy and work efficiency.

[0029] By collecting multi-dimensional environmental parameters such as temperature, humidity, and particulate matter concentration in real time using environmental sensor components, and combining them with a dynamic wavelength ratio correction algorithm to achieve accurate compensation for infrared radiation transmission attenuation, the device effectively resists the interference of environmental factors on temperature measurement results and significantly improves the working stability of the device in complex environments.

[0030] The thermoelectric cooler works in conjunction with the detector noise feedback circuit to precisely control the detector's operating temperature, effectively reducing the impact of temperature fluctuations on the detector's noise level, ensuring that the detector is always in optimal working condition, and further improving signal detection accuracy and temperature measurement reliability.

[0031] The inert gas curtain sprayed by the air curtain nozzle can effectively isolate dust, frost and other interference during calibration and temperature measurement in harsh environments, protect the light transmission performance of the optical lens, ensure stable transmission of infrared signals, and significantly expand the applicability of the device in a variety of harsh scenarios.

[0032] To better illustrate this disclosure in detail, several specific embodiments are provided below for reference: Example 1 This embodiment is applicable to conventional industrial environments such as machining workshops, and is used to realize non-contact temperature measurement of workpiece surfaces. Its suitable ambient temperature and humidity range is -10℃ to 50℃, and the ambient particulate matter concentration is ≤100μg / m³.

[0033] In this embodiment, the specific parameter settings for each component of the temperature measuring device are as follows: The optical lens is an infrared optical lens with a focal length of 25mm, used to efficiently receive the infrared light radiated by the target workpiece. The beam splitting module uses a dichroic beam splitter, which can accurately separate the incident infrared light into two wavelength channels, λ1 (1.4μm–1.6μm) and λ2 (1.8μm–2.0μm). The first detector (adapted to the λ1 channel) and the second detector (adapted to the λ2 channel) of the stacked dual detector assembly are both made of InGaAs material and are fabricated on both sides of an alumina insulating substrate by photolithography integration process. The central axis of the two detectors are aligned with an accuracy of ≤0.01mm, and each is equipped with a bandpass filter adapted to the corresponding wavelength. The high-emissivity area of ​​the calibration board is a copper substrate with a silicon carbide coating (2mm thick, coating emissivity 0.96), while the low-emissivity area is a polished aluminum plate (2mm thick, emissivity 0.08). Rotation is driven by a stepper motor (rotary motor) in conjunction with a Hall effect sensor to achieve a positioning accuracy of ≤0.5°. Environmental sensor components include an SHT30 temperature and humidity sensor (temperature measurement accuracy ±0.2℃, humidity measurement accuracy ±2%RH) and a PMS5003 particulate matter concentration sensor. The signal processing circuit uses an FPGA chip as the core processing unit, with pre-stored wavelength-attenuation relationship matrix adapted to typical industrial environments. The thermal insulation substrate is an aluminum nitride ceramic substrate with a built-in TEC1-12706 thermoelectric cooler. Its cold-end temperature measurement accuracy is ≤0.1℃, and the hot end is fixedly connected to aluminum alloy heat sink fins. The surface of the heat sink fins is coated with thermal grease to enhance heat dissipation. The device housing is made of aluminum alloy, the air curtain nozzle is made of stainless steel, the injection medium is nitrogen, and the air curtain flow rate is controlled at 0.5L / min.

[0034] The working process of this embodiment is as follows: After the device is started, the rotary motor drives the calibration plate to rotate to the position of avoiding the light path (i.e., avoiding the light-transmitting area), and the device enters the working mode. The optical lens receives the infrared light radiated by the target object, which is separated into two wavelength channels by the dichroic beam splitter. These signals are received by the two detectors of the stacked dual detector assembly and converted into the first electrical signal. The environmental sensor assembly collects temperature, humidity, and particulate matter concentration data in the workshop in real time and transmits them synchronously to the signal processing circuit. The signal processing circuit queries the pre-stored wavelength-attenuation relationship matrix based on the received environmental parameters, calculates and outputs the dynamic compensation coefficient, and corrects the electrical signal output by the dual detectors through the dynamic wavelength ratio correction algorithm to finally obtain the accurate workpiece surface temperature value (i.e., the actual temperature value). To ensure measurement accuracy, the temperature measuring device can be set to automatically enter the calibration mode every 2 hours: the rotary motor drives the calibration plate to rotate, allowing the high emissivity area or low emissivity area to enter the light path. The signal processing circuit calibrates the detector based on the preset standard emissivity value. After calibration, the rotary motor drives the calibration plate to reset, and the device returns to the working mode. During the calibration process, nitrogen gas is sprayed simultaneously from the air curtain nozzles to prevent dust in the workshop from interfering with the calibration accuracy.

[0035] Example 2 This embodiment is applicable to high-temperature industrial environments such as steel smelting and glass manufacturing, and is used to realize non-contact temperature measurement of high-temperature workpieces. The temperature range of the target object is 500℃~2000℃, the ambient temperature and humidity range is 0℃~80℃, and the ambient particulate matter concentration is ≤500μg / m³.

[0036] To address the unique challenges of high-temperature environments, this embodiment optimizes the temperature measurement device as follows: The optical lens is a high-temperature resistant quartz glass lens, with an anti-reflection coating on the lens surface to reduce reflection loss from high-temperature radiation. The beam splitter module uses a high-temperature resistant dichroic beam splitter with an operating temperature range of -20℃ to 120℃. The insulating substrate of the stacked dual-detector assembly is a high-temperature resistant silicon nitride ceramic substrate, the detector is made of high-temperature adaptable InGaAs material, and the bandpass filter is made of high-temperature resistant optical glass. The calibration plate substrate is made of high-temperature resistant stainless steel, with a high-temperature silicon carbide coating (temperature resistance ≥2000℃, emissivity 0.97) applied to high-emissivity areas, and a polished high-temperature alloy plate (emissivity 0.09) used for low-emissivity areas. The rotary motor is a high-temperature resistant stepper motor equipped with a high-temperature protective cover. The environmental sensor assembly uses a high-temperature resistant temperature and humidity sensor (measurement range 0℃~80℃) and a high-temperature resistant particulate matter concentration sensor. The signal processing circuit incorporates a high-temperature heat dissipation module, employing a composite heat dissipation structure with an aluminum alloy shell and a cooling fan. The heat-insulating substrate is made of high-temperature resistant zirconia ceramic, with a built-in high-power TEC1-12710 thermoelectric cooler (10W cooling power). Its hot end is connected to a large copper heat sink fin, and a cooling fan is used to enhance heat dissipation. The gas curtain nozzle has an increased nozzle diameter, increasing the gas curtain flow rate to 1.5L / min, and argon gas, which has stronger high-temperature resistance and stability, is used as the spray medium. The device shell is made of high-temperature resistant heat-insulating material, and the inner wall is lined with heat-insulating cotton to prevent the high ambient temperature from affecting the internal components.

[0037] The advantages of this embodiment are as follows: The optimized temperature measurement device, through the selection of high-temperature resistant components across the entire chain, can stably adapt to the harsh conditions of high-temperature industrial environments. The high-power thermoelectric cooler, combined with a composite heat dissipation structure, effectively offsets the impact of high ambient temperatures on the detector, ensuring stable detector operating temperature. The high-flow-rate argon calibration gas curtain effectively isolates dust and high-temperature airflow in high-temperature, high-dust environments, ensuring calibration and temperature measurement accuracy. The dynamic wavelength ratio correction algorithm optimizes the wavelength-attenuation relationship matrix for the infrared radiation characteristics of high-temperature environments, further improving the temperature measurement accuracy of high-temperature target objects.

[0038] Example 3 This embodiment is applicable to harsh environments with high dust concentrations, such as mining and tunnel construction, and is used to measure the temperature of target objects such as mining equipment motors and tunnel walls. The applicable target object temperature range is -20℃ to 300℃, the environmental particulate matter concentration is ≤1000μg / m³, and the environmental humidity range is 30%RH to 95%RH.

[0039] To address the challenges of high dust and high humidity environments, this embodiment features the following optimized design for the device: The optical lens is equipped with an automatic cleaning brush assembly, working in conjunction with an air curtain nozzle for dual dust protection. The cleaning brush is driven by a micro-motor and automatically cleans the lens surface every hour. The optical surface of the beam splitter is coated with an anti-fouling film to reduce the probability of dust adhesion. The calibration plate is coated with an anti-dust adhesion coating to prevent dust accumulation from affecting emissivity characteristics. The environmental sensor assembly utilizes a high-sensitivity particulate matter concentration sensor (measurement range 0~1000μg / m³) and a moisture-proof temperature and humidity sensor. The signal processing circuit optimizes the dynamic wavelength ratio correction algorithm, enhancing the calculation accuracy of the infrared radiation attenuation compensation coefficient in high dust concentration environments. The thermoelectric cooling element of the heat insulation substrate employs a moisture-proof encapsulation design to prevent short-circuit failures caused by high humidity. The device housing adopts a sealed design with an IP65 protection rating, and all interfaces use sealed connectors. The air curtain nozzles adopt a ring layout, with multiple nozzles arranged around the optical lens to form a 360° gas curtain without dead angles. The air curtain flow rate is controlled at 2.0L / min, and the spray medium is dry nitrogen, which also has a dehumidification function.

[0040] The advantages of this embodiment are as follows: The dual dustproof design of the annular calibration air curtain and the automatic cleaning brush effectively blocks high-concentration dust from contaminating the optical lens, ensuring stable transmission of infrared signals. The selection of a sealed housing and moisture-proof components ensures long-term stable operation of the device in high-humidity and high-dust environments. The optimized dynamic wavelength ratio correction algorithm accurately compensates for the attenuation effect of dust and humidity on infrared radiation, significantly improving the temperature measurement accuracy and reliability of the device in harsh mining environments.

[0041] Example 4 This embodiment is applicable to precision electronic manufacturing environments such as semiconductor chip manufacturing and electronic component packaging. It is used to realize temperature measurement of precision devices such as chips and circuit boards. The temperature measurement accuracy requirement is ≤±0.1℃, the ambient temperature and humidity range is 20℃~25℃ (constant temperature and humidity), and the ambient particulate matter concentration is ≤10μg / m³ (cleanroom environment).

[0042] To address the high-precision temperature measurement requirements and cleanroom environment constraints of precision electronic manufacturing, this embodiment optimizes the temperature measurement device as follows: A high-resolution infrared lens with a focal length of 50mm is selected to ensure precise focusing on minute precision components. A high-precision dichroic beam splitter is used in the beam splitter module, with wavelength separation accuracy ≤0.01μm. The stacked dual-detector assembly employs a high-precision InGaAs detector (noise level ≤1nV / √Hz), a high-precision ceramic substrate is used as the insulating substrate, and the central axis alignment accuracy of the photolithography integration process is ≤0.005mm. A narrow-band filter (bandwidth 0.05μm) is used for the bandpass filter to further improve wavelength selectivity. The high-emissivity area of ​​the calibration plate uses an ultra-high emissivity silicon carbide coating (emissivity 0.99), while the low-emissivity area uses an ultra-polished aluminum plate (emissivity 0.05). A high-precision servo motor is used for the rotary motor, working in conjunction with a Hall sensor to achieve a positioning accuracy of ≤0.1°, ensuring calibration accuracy. The environmental sensor components utilize ultra-high precision temperature and humidity sensors (temperature measurement accuracy ±0.05℃, humidity measurement accuracy ±1%RH) and a laser particulate counter (measurement accuracy 0.1μg / m³). The signal processing circuit employs a high-performance FPGA+ARM dual-core architecture to improve data processing speed and accuracy. The dynamic wavelength ratio correction algorithm uses a neural network optimization model to further improve the calculation accuracy of the compensation coefficient. The thermoelectric cooling element of the heat insulation substrate is a high-precision model with a cooling temperature control accuracy ≤0.01℃. Combined with the high-precision closed-loop control of the detector noise feedback circuit, it ensures the extreme stability of the detector's operating temperature. The device housing is made of stainless steel with an anti-static treatment to avoid interference with the precision electronic manufacturing environment. The calibration gas curtain uses high-purity nitrogen (purity ≥99.999%), with a flow rate controlled at 0.2L / min to prevent airflow from affecting precision components.

[0043] The advantages of this embodiment are as follows: The high-precision selection of optical components, detectors, and calibration structures ensures ultra-high temperature measurement accuracy, meeting the precise temperature measurement requirements of micro-devices in precision electronics manufacturing. High-performance signal processing circuitry and optimized dynamic wavelength ratio correction algorithms further enhance the accuracy and stability of temperature measurement. The anti-static, low-airflow structural design meets the requirements of cleanrooms and precision electronics manufacturing environments, and will not interfere with the production process.

[0044] Example 5 This embodiment is applicable to low-temperature environments such as food cold chain storage and low-temperature logistics carriages. It is used to measure the temperature of target objects such as refrigerated food and cold chain equipment pipelines. The temperature range of the target objects it is compatible with is -50℃ to 20℃, the ambient temperature and humidity range is -50℃ to 0℃, and the humidity range is 20%RH to 80%RH. There is a risk of frost formation.

[0045] To address the challenges of low-temperature and frost-prone environments, this embodiment optimizes the temperature measurement device as follows: A low-temperature-adaptive infrared lens is selected for the optical lens, with an anti-frost coating on the lens surface to prevent frost formation from affecting infrared signal reception in low-temperature environments. The beam splitter module employs a low-temperature-stable dichroic beam splitter to ensure stable wavelength separation accuracy at -50℃. The insulating substrate of the stacked dual-detector assembly is made of a low-temperature-resistant, tough ceramic substrate to prevent low-temperature brittleness. The detector uses low-temperature, low-noise InGaAs material to ensure signal detection sensitivity at low temperatures. The calibration board substrate is made of low-temperature-resistant stainless steel, and the coating in the high / low emissivity areas undergoes low-temperature curing treatment to ensure stable emissivity at low temperatures. The rotary motor is a low-temperature-resistant stepper motor equipped with a heating insulation jacket (for auxiliary heating during low-temperature startup). The environmental sensor assembly includes a low-temperature-resistant temperature and humidity sensor (measurement range -50℃~60℃) and an anti-frost particulate matter concentration sensor. The signal processing circuit incorporates a low-temperature insulation module wrapped in heat-insulating cotton, and the core chip is equipped with a miniature heating element to ensure an operating temperature ≥0℃. The thermal insulation substrate is made of high-insulation aluminum nitride ceramic substrate, and the built-in thermoelectric cooling chip is a low-temperature adapted model. Combined with the detector noise feedback circuit, the temperature control strategy is optimized to prevent frost formation due to excessive temperature difference between the detector and the environment. The device shell adopts a sealed and insulated design, with the inner wall filled with polyurethane insulation cotton, achieving an IP66 protection rating. The calibration gas curtain uses dry nitrogen (dew point ≤ -40℃), with a flow rate controlled at 0.4L / min, and also has anti-frost and defrosting functions to prevent frost formation on the optical lens.

[0046] The advantages of this embodiment are as follows: The dual anti-frost design of the anti-frost coating and the dry nitrogen gas curtain effectively avoids the frosting problem of the optical lens in low-temperature environments, ensuring stable transmission of infrared signals. The selection of low-temperature resistant components and the design of the insulation structure ensure stable operation of the device in a -50℃ environment. The optimized temperature control strategy balances the detector's operating temperature with the ambient temperature difference, ensuring detection accuracy while reducing the risk of frosting. It can accurately measure the temperature of target objects in cold chain environments, meeting the needs of food cold chain safety monitoring.

[0047] Example 6 This embodiment is applicable to medical scenarios such as hospitals and community health service centers, and is used to measure the temperature of the human body surface (such as the forehead and wrist). The temperature range of the target object is 32℃~42℃, the measurement accuracy is required to be ≤±0.05℃, the ambient temperature and humidity range is 18℃~30℃, the humidity range is 30%RH~70%RH, and it must meet medical and health safety requirements.

[0048] To address the high-precision temperature measurement requirements and hygiene and safety standards in medical settings, this embodiment features the following optimized design for the device: A short focal length (10mm) infrared lens is selected to ensure accurate temperature measurement at close range (5cm~15cm). An antibacterial coating is applied to the lens surface for easy cleaning and disinfection. The beam splitter module employs a miniaturized, high-precision dichroic beam splitter with a wavelength separation accuracy ≤0.008μm. The stacked dual-detector assembly utilizes an ultra-high precision, low-noise InGaAs detector (noise level ≤0.5nV / √Hz), with a central axis coincidence accuracy ≤0.003mm. A narrow-band filter (bandwidth 0.03μm) is used for the bandpass filter to improve the selectivity of infrared radiation signals from the human body. The calibration plate adopts a miniaturized design with a diameter ≤15mm. The high-emissivity area uses a medical-grade antibacterial silicon carbide coating (emissivity 0.98), while the low-emissivity area uses a medical-grade polished stainless steel plate (emissivity 0.06). The rotary motor is a silent micro servo motor with a positioning accuracy ≤0.05°. The environmental sensor component uses a high-precision temperature and humidity sensor (temperature measurement accuracy ±0.03℃, humidity measurement accuracy ±1%RH) to collect ambient temperature data in real time to correct human body surface temperature measurements. The signal processing circuit uses a low-power ARM chip, and the dynamic wavelength ratio correction algorithm is optimized for human infrared radiation characteristics, integrating a human body temperature compensation model. The heat insulation substrate uses a lightweight ceramic substrate, and the thermoelectric cooling element is a miniature, high-precision model with a cooling temperature control accuracy ≤0.005℃, ensuring stable detector operating temperature. The device housing is made of medical-grade ABS material with an antibacterial coating for easy high-frequency sterilization. Its size is ≤100mm×60mm×30mm, and its weight is ≤200g. It is equipped with a rechargeable lithium battery (battery life ≥12 hours). The calibration air curtain uses medical-grade high-purity nitrogen (purity ≥99.999%), with an air curtain flow rate controlled at 0.1L / min to avoid discomfort to the human body.

[0049] The advantages of this embodiment are as follows: The ultra-high precision detection and calibration structure design ensures accurate measurement of human body surface temperature, meeting the high-precision requirements of medical temperature measurement. The comprehensive application of medical-grade antibacterial materials and coatings meets the hygiene and safety requirements of medical scenarios. The miniaturized, lightweight design and long battery life facilitate handheld use by medical personnel. The in-situ calibration function allows for rapid calibration during medical breaks, ensuring the stability of temperature measurement accuracy while avoiding the risk of cross-infection.

[0050] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A temperature measuring device, characterized in that, The temperature measuring device includes: case; An optical lens for receiving infrared light radiated by a target object; A beam splitting module is located on the rear optical path of the optical lens and is used to separate incident infrared light into a first wavelength channel and a second wavelength channel. A calibration plate is rotatably disposed in the optical path between the optical lens and the beam splitter module. The plate has a high emissivity region, a low emissivity region, and a light-avoiding region. The calibration plate is driven to rotate by a rotary motor connected to it, so as to selectively cut the high emissivity region, the low emissivity region, or the light-avoiding region into the optical path, thereby realizing the switching between the working mode and the calibration mode. A stacked dual detector assembly includes a first detector and a second detector stacked along the optical path direction, which are respectively used to receive optical signals from the first wavelength channel and the second wavelength channel and convert them into a first electrical signal. An environmental sensor assembly is disposed in the housing. The environmental sensor assembly includes a temperature and humidity sensor and a particulate matter concentration sensor, which are used to collect environmental temperature and humidity and particulate matter concentration parameters and convert them into a second electrical signal, respectively. The signal processing circuit is electrically connected to the stacked dual detector assembly and the environmental sensor assembly, respectively, and is used to receive the first electrical signal and the second electrical signal, and calculate and output the temperature value through the built-in dynamic wavelength ratio correction algorithm. The stacked dual detector assembly, beam splitter module, calibration plate, and optical lens are sequentially stacked on the housing along the optical path direction.

2. The temperature measuring device according to claim 1, characterized in that, The temperature measuring device also includes a heat-insulated temperature control module; The thermal insulation temperature control module includes a thermal insulation substrate and a thermoelectric cooling chip embedded inside the thermal insulation substrate; one side of the thermal insulation substrate is fixedly connected to the housing, and the other side is used to support the stacked dual detector assembly.

3. The temperature measuring device according to claim 2, characterized in that, The stacked dual detector assembly also includes an insulating substrate; The first detector and the second detector are respectively fabricated on the front and back sides of the insulating substrate by photolithography integration process, and their photosensitive central axes are collinear and coincident; the photosensitive surface of the first detector is covered with a bandpass filter adapted to the wavelength of the first wavelength channel, and the photosensitive surface of the second detector is covered with a bandpass filter adapted to the wavelength of the second wavelength channel.

4. The temperature measuring device according to claim 3, characterized in that, The cold end of the thermoelectric cooling chip is thermally connected to the insulating substrate, and its hot end is fixedly connected to the heat dissipation fins.

5. The temperature measuring device according to claim 4, characterized in that, The cooling temperature of the thermoelectric cooler is controlled in a closed loop by a detector noise feedback circuit. The input of the detector noise feedback circuit is electrically connected to the stacked dual detector assembly, and its output is electrically connected to the control terminal of the thermoelectric cooler.

6. The temperature measuring device according to claim 1, characterized in that, The wavelength range of the first wavelength channel is 1.4μm–1.6μm, and the wavelength range of the second wavelength channel is 1.8μm–2.0μm.

7. The temperature measuring device according to any one of claims 1 to 6, characterized in that, The high emissivity region is a structure formed by spraying a silicon carbide coating onto the surface of a copper substrate, with an infrared emissivity greater than 0.95; the low emissivity region is a structure formed by polishing the surface of an aluminum substrate, with an infrared emissivity less than 0.1; the light-blocking region is a through-hole structure. The calibration plate is provided with multiple positioning grooves spaced circumferentially along its edge. The positioning grooves cooperate with the Hall sensor on the rotary motor to achieve precise positioning of the rotation angle.

8. The temperature measuring device according to any one of claims 1 to 6, characterized in that, The signal processing circuit has a wavelength-attenuation relationship matrix pre-stored inside; The execution of the dynamic wavelength ratio correction algorithm includes: based on the received first and second electrical signals, calculating the dynamic compensation coefficient through the wavelength-attenuation relationship matrix, and correcting the ratio of the dual-wavelength electrical signals output by the stacked dual detector assembly to obtain the actual temperature value.

9. The temperature measuring device according to any one of claims 1 to 6, characterized in that, The temperature measuring device also includes at least one air curtain nozzle disposed in the housing; The air curtain nozzle is connected to an inert gas source and is used to spray an inert gas curtain onto the optical path in front of the optical lens during calibration mode or temperature measurement in harsh environments, so as to isolate the interference of environmental dust on the optical path.

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