hệ thống cảm biến sợi quang

Hệ thống cảm biến nhiệt độ sợi quang huỳnh quang

Cảm biến nhiệt độ sợi quang huỳnh quang bao gồm một sợi quang đa mode và một vật thể huỳnh quang (phim ảnh) gắn trên nó. Nguyên lý hoạt động của nó dựa trên năng lượng huỳnh quang phát ra từ chất huỳnh quang dưới bước sóng cụ thể (phổ kích thích) kích thích ánh sáng. Sau khi ngừng kích thích, Sự tồn tại của ánh sáng phát huỳnh quang bị ảnh hưởng bởi các yếu tố như đặc tính của chất huỳnh quang và nhiệt độ môi trường. Sự phát huỳnh quang thường phân rã theo cấp số nhân, và hằng số thời gian phân rã là thời gian sống huỳnh quang hoặc thời gian phát sáng huỳnh quang (ns). Hơn thế nữa, sự phân rã ánh sáng huỳnh quang thay đổi ở nhiệt độ môi trường khác nhau. Vì thế, nhiệt độ môi trường có thể được xác định bằng cách đo thời gian tồn tại của ánh sáng huỳnh quang.

Hệ thống cảm biến này có nhiều ưu điểm. Trước hết, the core technology lies in fluorescent substances and corresponding simulation algorithms. The technical principle and product structure are simple, và temperature measuring fluorescent material used is calcined at 1200 độ C, which has extremely long lifespan and stable and reliable working characteristics. It is very suitable for large-scale industrial mass production and widely used in the industrial field. Thứ hai, pure fiber optic probes have the characteristics of intrinsic safety, cách điện cao áp, và khả năng chống nhiễu điện từ; The system operates stably without drift and does not require calibration or verification throughout its entire lifespan; Adopting modular design, it can be flexibly networked and infinitely expanded at any time without causing resource waste; Equipped with digital and analog outputs, it is convenient for automated real-time control and data management; The probe and demodulator are compact and flexible, dễ dàng cài đặt và bảo trì. It is widely used in various application fields. In the field of power grid, it can be used to monitor the temperature of hot spots such as switchgear and transformers, detect temperature anomalies in a timely manner, and ensure the safe and stable operation of power; In the field of laboratory research, it is possible to monitor the temperature changes of reaction systems in chemical experiments to ensure the accuracy of experimental results, and in biological experiments, it is possible to monitor the temperature distribution inside the organism, which helps medical researchers study the thermal stability of organisms; Trong lĩnh vực y tế, temperature changes of patients can be monitored during surgery to ensure smooth operation, và có thể được sử dụng trong các trung tâm phục hồi chức năng để đánh giá tình trạng hồi phục của bệnh nhân. Ngoài ra, nó có những ưu điểm riêng trong nhiều tình huống đặc biệt, chẳng hạn như đo nhiệt độ bên trong của gà viên trong ngành thực phẩm để đảm bảo bên trong chín và bề mặt không bị cháy trong quá trình nướng; Khi việc ghép chính xác các linh kiện nhỏ được thực hiện trong ngành công nghiệp điện tử trong môi trường vi sóng để theo dõi nhiệt độ, Nhiệt kế cặp nhiệt điện truyền thống không thể đo chính xác do ảnh hưởng của vi sóng, trong khi cảm biến nhiệt độ sợi quang huỳnh quang có ưu điểm rõ ràng là không bị ảnh hưởng bởi nhiễu điện từ. Các thí nghiệm đã chỉ ra rằng trong kịch bản này, Nhiệt kế sợi quang đọc chính xác và không bị ảnh hưởng bởi các yếu tố bên ngoài, while thermocouple thermometers have large errors.

Multi domain related application supplement

In addition to the common application areas mentioned earlier, cảm biến nhiệt độ sợi quang huỳnh quang also have important value in other industries. In the petrochemical industry, places such as refineries have flammable, chất nổ, and corrosive environments. The intrinsic safety and corrosion resistance of fluorescent fiber optic temperature sensors enable them to effectively monitor the temperature of pipelines, reaction vessels, và các thiết bị khác, ensuring that the production process is carried out under appropriate temperature conditions and the safety of personnel and equipment is guaranteed. In the aerospace field, temperature detection can be performed on key components such as engines, which requires sensors to have high accuracy, chịu nhiệt độ cao, và khả năng chống nhiễu điện từ. Fluorescent fiber optic temperature sensors can precisely meet these requirements and help improve the safety and reliability of aerospace equipment operation. In the field of new energy such as solar power generation, temperature measurement can be carried out on solar panels to optimize their energy conversion efficiency through temperature data acquisition. Once the temperature is too high and affects the power generation efficiency, timely adjustment measures can be taken. In short, the characteristics of fluorescent fiber optic temperature sensors enable them to continuously open up new application scenarios in many fields with special requirements for temperature detection.

Hệ thống cảm biến sợi quang phân tán

các cáp quang phân tán sensing network system is a network system that integrates sensing, điều khiển, và các chức năng khác. It uses optical fiber as a sensing medium, which can sense external physical quantities by changing its characteristics such as wavelength, giai đoạn, and intensity. Đồng thời, optical fiber can be well integrated with optical fiber sensing network systems as a communication medium. This system has the characteristics of anti electromagnetic interference, độ tin cậy cao, and long-distance distributed monitoring, and has broad application value and market prospects.

From a technical perspective, nonlinear optical effects such as Raman and Brillouin effects in fiber optics are used to detect environmental temperature and pressure induced stress. Ví dụ, Raman scattering is used for distributed temperature sensing (DTS), có thể xác định chính xác nhiệt độ tại bất kỳ vị trí nhất định nào dọc theo sợi bằng cách đo sự khác biệt về cường độ ánh sáng tán xạ ngược trong dải Stokes và phản Stokes; Nguyên lý tán xạ Brillouin tương tự, trong đó bước sóng của ánh sáng tán xạ ngược bị ảnh hưởng bởi nhiệt độ bên ngoài và kích thích âm thanh theo cách có thể dự đoán được. Bằng cách kết hợp dữ liệu này với kiến ​​thức cơ bản về nhiệt độ tại cùng một điểm, sức căng của sợi có thể được xác định chính xác, và khu vực nào của sợi bị ảnh hưởng có thể được phân tích.

Nó đóng vai trò không thể thay thế trong nhiều lĩnh vực. Về mặt giám sát an ninh, nó là một thiết bị mới rất bắt mắt của công nghệ cảm biến sợi quang, which can achieve perimeter monitoring and alarm for special locations such as airports, borders, căn cứ, cổng, vân vân; Safety monitoring of oil/gas pipelines and refinery oil pipelines; It can achieve tunnel excavation detection for special locations such as military bases, nhà tù, banks, and nuclear power plants, and timely detect potential threats; The long-distance distributed monitoring capability for optical cables in government, banking, intelligence agencies, and other locations is beyond the reach of traditional sensors. And it also has applications in industrial monitoring, such as temperature scanning of grain warehouses and oil depots to comprehensively understand temperature distribution and achieve more accurate monitoring. It can also be used for distributed temperature and strain monitoring of various structures such as bridges, đập nước, đường hầm, vân vân.

In terms of technical indicators and practical application characteristics, it is clearly reflected in a distributed fiber optic sensing early warning system. The single core positioning technology designed with a dual core optical path saves fiber resources and improves positioning accuracy compared to the international three core positioning technology; The system is divided into two types: fence type and buried type to adapt to different application scenarios of surface fences (such as wrought iron, wire mesh, fences, walls, vân vân.) and underground (such as grasslands, gravel layers, cement floors, and ordinary soil); The warning system surpasses similar foreign systems in key technologies such as light intensity, trạng thái phân cực, polarization angle, optical signal frequency, giai đoạn, optical phase locking, chaotic neural network recognition algorithm, and fusion technology; It has the advantages of truly passive front-end sensing and transmission, easy construction, và chi phí thấp (using ordinary communication optical cables as sensors); There are also multiple monitoring methods available, which can display real-time time-domain waveforms of fiber optic cable disturbances, monitor interference sounds along the fiber optic cable, count the number of fiber optic cable disturbance events at different time periods or distances, accurately classify and identify fiber optic cable disturbances along the route, and display alarms on geographic information diagrams; There are corresponding parameters and requirements for technical indicators such as response time, đáp ứng tần số, fiber optic service life, alarm probability, false alarm probability, monitoring distance, positioning accuracy, and working temperature.

Supplement to the New Application Trends of Distributed Fiber Optic Systems

With the further development of technology, cái application scenarios of distributed fiber optic sensing systems are constantly expanding and extending. In the field of urban rail transit, the health status of subway tunnel structures can be monitored. By laying distributed fiber optic sensors inside or around the tunnel walls, changes in key parameters such as strain and temperature of the tunnel can be sensed in real time. If there are structural deformations (possibly caused by geological changes, earthquakes, vân vân.) or temperature anomalies (such as fire hazards, vân vân.), the system can provide timely feedback data for the operator to take measures to prevent safety accidents from occurring. In the construction of smart grids, distributed fiber optic sensing systems can dynamically monitor ultra-high voltage transmission lines. They not only rely on traditional temperature monitoring to ensure the safe operation of the lines (as high line temperatures may increase line losses and make them prone to faults), but also monitor the mechanical properties of the lines (such as tension, sự căng thẳng, vân vân.) by reflecting changes in fiber optic characteristics caused by physical quantities through cảm biến sợi quang, making the entire power grid more intelligent and reliable. Ngoài ra, there are potential applications and development prospects in the field of ocean engineering, such as monitoring submarine cables and monitoring the structural health of offshore oil platforms, to safeguard the development and utilization of marine resources.

Fiber Bragg Grating Temperature Sensing System

Công nghệ cảm biến Fiber Bragg Grated sử dụng cách tử Bragg sợi làm phần tử cảm biến để đo các đại lượng vật lý thông qua sợi quang, và cảm biến nhiệt độ là loại cảm biến được sử dụng rộng rãi. Lưới sợi Bragg (FBG) là một bộ phản xạ quang học chọn lọc tần số được chế tạo bằng nguyên lý sợi quang. Dưới sự kích thích của nguồn sáng, tín hiệu quang đi tới cách tử qua sợi quang và bị phản xạ trở lại. Sự thay đổi về lượng cảm nhận của FBG có thể được xác định từ cường độ ánh sáng phản xạ và phân bố bước sóng.

Nguyên lý cảm biến nhiệt độ cách tử sợi quang dựa trên sự thay đổi bước sóng Bragg cách tử do thay đổi nhiệt độ. Quang phổ phản xạ được ghi lại bởi camera CCD, and the reflected light signal is processed by a signal processor to achieve temperature measurement. In terms of control system, if a temperature control system is built based on fiber Bragg grating sensing technology, it mainly consists of four parts: signal acquisition, xử lý tín hiệu, control module, and actuator. The fiber Bragg grating sensor in the signal acquisition process transmits the collected signals to the signal processing module for preprocessing; The signal processing module is based on the collected temperature and is controlled by an incremental PID controller for temperature related control; The control module can adopt an embedded system, which can communicate with the upper computer, achieve real-time monitoring of temperature and control standards, and be used for developing other advanced applications; The executing mechanism includes DC motor, variable frequency motor, stepper motor, vân vân.

Fiber Bragg grating temperature sensors have multiple advantages. Trước hết, it has high sensitivity, which is related to its sensing technology principle and can accurately sense temperature changes; Thứ hai, it does not require an external power supply and is not affected by electromagnetic interference. Ngoài ra, its probe can resist mechanical, điện từ, and chemical interference well, and can reliably measure physical quantities in harsh environmental conditions such as oil and gas exploration (often with complex electromagnetic interference and possible chemical corrosion environments), hàng không vũ trụ (with various complex radiation and other interference sources in space and special requirements for equipment weight), medical diagnosis (with numerous surrounding devices in medical environments, complex electromagnetic environments and high requirements for detection equipment safety), and industrial process control (affected by electromagnetic field environments and various chemical substances in industry); And it has the characteristics of high stability, not affected by light intensity and spots, as well as advantages such as small size, trọng lượng nhẹ, thời gian phản hồi nhanh, chống nhiễu điện từ, and strong corrosion resistance, which make it more competitive than other types of sensors in a wide range of application scenarios. Ngoài ra, cái fiber Bragg grating temperature sensing technology based on phase sensitive detection is worth mentioning. This is a commonly used fiber Bragg grating temperature sensing technology, which uses an interferometer to coherently interfere the reflected light of FBG (lưới sợi Bragg) with the reference light, thereby improving the sensitivity and stability of the sensor. It has achieved ultra-high sensitivity at the sub millikelvin level, making it particularly suitable for precise measurement of small temperature changes, such as in biomedical imaging, microfluidics, and nanotechnology, and has broad application prospects.

Fiber Bragg Grating technology involves the supplementation of special materials

In the production and application of fiber Bragg grating temperature sensing systems, research and application of some special materials or structures are involved. The production of fiber optic gratings has special requirements, and the material composition of the fiber core and cladding needs to be precisely controlled in order to achieve the desired optical properties such as refractive index changes of the grating accurately. Ví dụ, fibers doped with specific elements such as germanium can optimize the performance of gratings. In terms of sensing applications, research on coating materials on the surface of fiber Bragg gratings is also constantly deepening. Special coating materials can enhance the corrosion resistance of fiber Bragg gratings or improve their interaction with the detected substance. Ví dụ, in some application scenarios of corrosion environment monitoring, by coating a corrosion-resistant and thermally conductive polymer coating, the grating itself is not corroded and the external temperature can be quickly transmitted to the grating area, making the measurement more accurate. There is also the selection and use of packaging materials for sensors. Suitable packaging materials can not only protect the fiber Bragg grating from working normally in complex external environments (such as high humidity, áp suất cao, vân vân.), but also minimize the impact on thermal conductivity during fiber Bragg grating temperature measurement. Ví dụ, composite materials with good sealing performance, appropriate thermal conductivity coefficient, and good rigidity and toughness can be used for packaging.

Overview of Fiber Optical Sensor Systems

Fiber optic sensor system is a sensing system based on optical fibers, including various types such as fluorescent fiber optic temperature sensing system, hệ thống cảm biến sợi quang phân tán, fiber optic grating temperature sensing system, vân vân. Each type has different characteristics in terms of principle, kết cấu, hiệu suất, vân vân. to adapt to different application scenarios.

Về nguyên tắc, it is to use the modulation of some characteristics of light (such as wavelength, cường độ, giai đoạn, vân vân.) by the fiber itself or the substances inside the fiber when light propagates in the fiber to reflect the information of external environmental changes, thus achieving the purpose of sensing and measurement. Ví dụ, the fluorescence fiber temperature sensing mentioned earlier is based on the relationship between fluorescence afterglow lifetime and temperature; Distributed fiber optic sensing utilizes phenomena such as Raman scattering and Brillouin scattering to measure physical quantities such as temperature or strain through differences in light intensity or wavelength changes; Fiber Bragg grating temperature sensing relies on temperature induced changes in grating Bragg wavelength to sense temperature.

Structurally, although there are differences among the systems, they are generally built around fiber optics. huỳnh quang fiber temperature sensing system consists of a fluorescent material module at the top of the fiber, a fiber transmission part, and a signal demodulator to achieve temperature sensing and other functions; The entire network construction of the distributed fiber optic sensing system includes the fiber optic network layout in the operation, module components connected to the fiber optic network for different functions (such as acquisition, xử lý, vân vân.), vân vân. The structure should ensure the ability to achieve continuous long-distance distributed measurement functions; The fiber optic grating temperature sensing system is built around the fiber optic grating, các thành phần quang học liên quan để thu thập và phân tích ánh sáng phản xạ từ cách tử, và cấu trúc của toàn bộ hệ thống điều khiển cảm biến nhiệt độ thông qua các module mạch bổ sung.

Về mặt hiệu suất, ba hệ thống phải đối mặt với các số liệu đánh giá khác nhau. Hệ thống cảm biến nhiệt độ sợi quang huỳnh quang tập trung vào độ chính xác của phép đo trong các phạm vi nhiệt độ khác nhau, sự ổn định của toàn bộ hệ thống (chẳng hạn như lợi thế quan trọng về độ ổn định là không yêu cầu hiệu chuẩn và xác minh trong suốt thời gian sử dụng), và các tính chất khác nhau của đầu dò (chẳng hạn như cách nhiệt, chống ăn mòn, sự an toàn, vân vân.); các cảm biến sợi quang phân tán hệ thống yêu cầu độ chính xác định vị, monitoring distance, đáp ứng tần số, vân vân. để đo khoảng cách xa, để nó có thể đóng một vai trò trong các tình huống ứng dụng như giám sát an toàn ở quy mô lớn và đường dài; The fiber Bragg grating temperature sensing system mainly focuses on the sensitivity and anti-interference performance of the sensor (chẳng hạn như nhiễu điện từ, chemical environmental interference, vân vân.), as well as the convenience of using the sensor in different target application fields (such as the influence of size and weight on installation and use in special environments, vân vân.).

Fiber optic sensor systems have a wide range of applications in various fields such as industrial manufacturing, năng lượng, giao tiếp, security and safety, hàng không vũ trụ, biomedicine, vân vân. due to their inherent ability to resist electromagnetic interference, feasibility of measuring multiple physical quantities, and adaptability in different environments. Ví dụ, in industrial manufacturing, monitoring the temperature, sự căng thẳng, and other conditions of equipment in complex electromagnetic field environments can be achieved using fiber optic sensor systems, thereby ensuring the automation of industrial production processes and timely warning and maintenance needs for monitoring equipment usage status; In the field of energy, monitoring and ensuring the safe operation of facilities such as oil and gas pipelines and power transmission lines can be improved through fiber optic sensor systems; In terms of security and safety, fiber optic sensing systems can be deployed around the perimeter and key facilities (such as nuclear power facilities) to enhance defense and monitoring capabilities.

Supplementary Development Trends of Fiber Optic Sensor Systems

With the development of materials science, optical technology and other related fields, fiber optic sensor systems are moving towards higher sensitivity, độ chính xác cao hơn, larger scale networking, and stronger adaptability to complex environments. New fiber optic materials are constantly being developed, which have advantages such as lower losses and higher optical performance, greatly improving the performance of fiber optic sensor systems in all aspects. Ví dụ, the development of special optical fibers enables sensors to work accurately and stably in extremely harsh environments such as high temperatures and strong corrosion. In terms of multifunctional integration, future fiber optic sensor systems may not be limited to measuring a single physical quantity (such as temperature or strain). A sensor system can simultaneously detect multiple physical quantities and perform comprehensive analysis to obtain more useful information. This requires further development in corresponding technologies such as integrated optics and intelligent algorithms. In terms of large-scale networking applications, with the development of new generation communication technologies such as 5G and the Internet of Things, hệ thống cảm biến sợi quang, as a monitoring method that can provide a large amount of raw data and has more advantages than traditional sensors, will play an increasingly important role in the construction of sensor networks for large-scale networking such as smart factories and smart cities in the future.

Comparison of various fiber optic sensor systems

 

1、 Comparison of Principle Characteristics

Hệ thống cảm biến nhiệt độ sợi quang huỳnh quang: With the help of fluorescent substances, the light characteristics of their fluorescence afterglow depend on temperature after being excited by specific light. The change in environmental temperature will cause a change in the decay mode of fluorescence afterglow, and temperature measurement can be achieved by detecting the length of fluorescence afterglow lifetime. This principle is based on the energy conversion and radiation characteristics between fluorescent substances and light, which is quite unique. Fiber optics mainly serve as channels for excitation light transmission and fluorescence transmission, and do not rely on the optical scattering or reflection phenomena of the fiber itself for sensing, unlike the other two systems. The sensitivity of the system under this principle can be adjusted according to the specific fluorescent substance selection and optimization algorithm, but in contrast, its response to temperature changes depends more on the inherent characteristics of the fluorescent substance, and the theoretical physical mechanism is directly related to the microscopic interaction between light and matter.
Distributed fiber optic sensing system: fully utilizing the characteristics of fiber optic itself as a continuous monitoring medium, utilizing nonlinear optical effects such as Raman scattering and Brillouin scattering in fiber optics. Under the Raman scattering mechanism, the difference in backscattered light intensity between Stokes and anti Stokes bands is measured to determine the temperature at a certain position of the fiber; When Brillouin scattering occurs, it is based on the influence of external factors (such as temperature and strain) on the wavelength of the backscattered light wave to grasp the physical quantities such as strain of the optical fiber. This principle based on the inherent scattering phenomenon of optical fibers enables continuous and distributed monitoring of physical quantities along the fiber without the need for additional sensing substances or structures to be added to the fiber. This principle determines that its monitoring is a continuous information acquisition method distributed along the optical fiber, and can measure longer distances. Tuy nhiên, the physical principle determines that its overall accuracy will be affected by factors such as weak scattered signals and noise.
Fiber Bragg Grating Temperature Sensing System: It works based on the principle that temperature changes cause changes in the Bragg wavelength of the fiber Bragg grating. This wavelength change is very precise, and temperature changes can be perceived by measuring the wavelength or spectral changes of reflected light. The core component, lưới sợi Bragg, is a periodic refractive index changing structure artificially manufactured in optical fibers. It is precisely this structure that produces specific reflection patterns for light and is significantly affected by temperature. The principle of wavelength modulation of light reflection based on specific optical structures enables sensors to have high accuracy and stability, and can be integrated with other optical systems to achieve higher sensitivity detection. Tuy nhiên, due to the complexity and stability requirements of grating structure fabrication, the system may face certain application limitations in terms of large-scale production costs or harsh environments (where Bragg wavelength is affected by external factors and there is a risk of non temperature induced deviation).

2、 Comparison of structural complexity

Hệ thống cảm biến nhiệt độ sợi quang huỳnh quang: The structure is relatively simple. It mainly consists of three parts: thăm dò (multimode fiber and top fluorescent material), transmission fiber, and signal demodulator. Fluorescent substances exist solely at the top of the optical fiber, directly receiving excitation light from the transmission fiber and transmitting the excited fluorescence to the demodulator through the fiber. This type of device structure is relatively simple and functionally clear, with clear modularity between different parts and a simple and straightforward manufacturing process. Although it also involves integrating fluorescent substances and attaching them to fiber ends, the overall complexity is not high. The large-scale production process is relatively easy to control, có khả năng tương thích tốt, and can be flexibly combined with different probes for use. It is convenient to layout probes for measurement in various simple or complex environments.
Distributed fiber optic sensing system: structurally more complex. The system has built a multifunctional detection and analysis system around fiber optic networks. Từ việc lựa chọn và lắp đặt sợi quang (xem xét sự khác biệt về tính chất sợi trong các môi trường khác nhau, bao gồm việc sử dụng cáp quang truyền thông thông thường và các phương pháp sử dụng tài nguyên khác), đến việc lắp đặt phân tán nhiều mô-đun phân tích và định vị khu vực cảm biến và giám sát dọc theo cáp quang. Nó không chỉ bao gồm việc tạo và truyền tín hiệu cơ bản, mà còn liên quan đến việc phát hiện tín hiệu quang học phức tạp, giải điều chế và phân tích tín hiệu sóng quang dưới tác động của các đại lượng vật lý khác nhau. Ví dụ, mô-đun đường dẫn quang yêu cầu xử lý phân tách và can thiệp, cũng như các bộ phận xử lý tín hiệu điện tử phức tạp liên quan đến xử lý DSP và phân tích tín hiệu rung động tốc độ cao để đạt được khả năng định vị và phán đoán sự kiện chính xác, multiple functional modules in the entire network system work together to achieve distributed monitoring and analysis of various physical quantities such as temperature and strain over long distances across regions. Vì thế, the structural complexity is relatively high. Once a fault or performance degradation occurs in a certain link of this structure, the troubleshooting and repair process is relatively cumbersome, but once it is successfully constructed, it can play a powerful distributed monitoring function.
Fiber Bragg Grating Temperature Sensing System: The structure is of moderate complexity. The core is the fiber optic grating component, and the production of fiber optic gratings itself requires specialized processes such as photolithography. Tuy nhiên, compared to distributed fiber optic sensing systems, its structure is relatively simple because it does not require complex distributed monitoring multi-point processing mechanisms. Tuy nhiên, when forming a complete temperature sensing system, it is also necessary to cooperate with a light source and devices for processing and analyzing reflected light (such as CCD cameras, bộ xử lý tín hiệu, and other equipment used to collect and process light signal changes based on grating reflection to obtain temperature information). Ngoài ra, when building a temperature control system, it is necessary to add components such as control modules and actuators to achieve overall control functions. Although the number of components is not as numerous as that of distributed fiber optic sensing systems, the overall structure requires accurate matching and collaborative work between fiber Bragg grating related optical components and auxiliary circuit control, phát hiện, and other links. There are also certain complexity requirements during system integration and debugging.

3、 Comparison of performance indicators

Hệ thống cảm biến nhiệt độ sợi quang huỳnh quang:
Độ chính xác của phép đo: The measurement accuracy of the system can be adjusted according to different needs, and the commonly used accuracy range covers ± 0.05 oC – ± 1 oC. Different products, kịch bản ứng dụng, vân vân. will adopt different accuracy levels, but overall, it can meet the needs of many industries and some special scenarios within a certain range. Tuy nhiên, its accuracy still depends relatively on factors such as the stability of the fluorescent substance and the degree of optimization of the measurement algorithm. Compared with fiber Bragg grating sensors, there may be a gap of 1 trong lĩnh vực có độ chính xác cao.
Phạm vi đo: Phạm vi đo nhiệt độ tương đối rộng, chia thành bốn phần: -40 oC -+80 oC- 40oC – +250oC；- 40oC – +400oC；+ 20 oC -+60 oC (thuộc về y học), có thể thích ứng với các yêu cầu về phạm vi nhiệt độ từ nhiệt độ lạnh đến nhiệt độ cao, từ môi trường dân sự thông thường đến môi trường y tế và sức khỏe đặc biệt, và nhiều tình huống sử dụng khác.
Hiệu suất chống nhiễu: Khả năng chống nhiễu điện từ mạnh mẽ. Do khả năng cách điện của sợi quang và nguyên lý phát quang và phát quang bên trong của chất huỳnh quang không liên quan đến nhiễu điện từ, nó vẫn có thể hoạt động ổn định ngay cả trong môi trường điện từ cao thế và phức tạp (như giám sát nhiệt độ của thiết bị gần thiết bị điện áp cao bên trong trạm biến áp điện). Đồng thời, the all fiber optic probe can adapt to various corrosive environments because it does not corrode any metal parts. This anti-interference advantage also makes it highly adaptable to different electrical, từ tính, and chemical environments, such as measuring material temperature inside chemical workshops.
Distributed fiber optic sensing system:
Độ chính xác của phép đo: In terms of accuracy, it is relatively limited due to its complex physical mechanisms such as Raman and Brillouin scattering, as well as various factors such as environmental noise and changes in fiber performance. In temperature measurement, although long-distance and large-scale monitoring can be achieved, the accuracy is relatively poor compared to specialized high-precision temperature sensors. Ví dụ, in the safety monitoring of long-distance oil pipelines, the main requirement for temperature accuracy is to detect a large range of temperature anomalies, and the requirement for absolute accuracy of temperature numerical accuracy is not a necessary condition.
Phạm vi đo: It can have a large adaptability range in temperature and strain monitoring, but the specific values often depend on various factors such as the type of optical fiber, the light source used in the system, and the detection device. Ví dụ, it can be used to monitor structural strain and temperature strain caused by relevant parameters in industrial environments ranging from room temperature to a certain high temperature or low temperature.
Hiệu suất chống nhiễu: The ability to resist electromagnetic interference is an important advantage, as it can work in strong electromagnetic field environments without interference. Đồng thời, optical fiber itself is a passive sensing and transmission medium, so it can work safely in some dangerous areas (such as underground coal mines for monitoring tunnel structures and temperature to prevent gas explosions and other hazards, without electrical risks such as electric sparks). Tuy nhiên, relatively speaking, it is more sensitive to damage to the fiber itself or environmental interference (such as excessive stretching and bending of the fiber, large fluctuations in local environmental temperature along the fiber, and measurement effects on scattered signals). Although there are many methods in design to reduce this impact, stability remains a challenge in performance evaluation.

Fiber Bragg Grating Temperature Sensing System:

Độ chính xác của phép đo: It has high measurement accuracy, which is based on the principle of extremely precise temperature modulation of fiber Bragg grating wavelength. Ví dụ, it can demonstrate its advantages in scenarios that require high precision, such as precision equipment and temperature monitoring of small areas within living organisms. It can achieve ultra-high sensitivity detection at sub millikelvin level, and provide accurate data in temperature monitoring of precision instruments and equipment, as well as detection scenarios where temperature changes are extremely subtle in the biomedical field.
Phạm vi đo: Although it can meet the needs in many scenarios, it poses significant challenges to the stability of optical materials and grating structures in extreme high or low temperature conditions, and its measurement range is not as wide as that of fluorescent fiber temperature sensing systems. Tuy nhiên, quy trình sản xuất đặc biệt và thiết kế tối ưu hóa cho các loại lưới Bragg sợi khác nhau có thể mở rộng một phần phạm vi đo để đáp ứng nhu cầu của nhiều loại tình huống hơn.
Hiệu suất chống nhiễu: Khả năng chống nhiễu điện từ mạnh mẽ, do dòng điện không yêu cầu kết nối bên ngoài và nguyên lý đo phản xạ quang học ổn định, nó ít bị ảnh hưởng bởi nhiễu điện từ bên ngoài. Có khả năng theo dõi độ ổn định nhiệt độ trong môi trường công nghiệp thông thường, thiết bị y tế môi trường điện tử, và một số môi trường nghiên cứu khoa học cơ bản nơi nhiều thiết bị điện từ cùng tồn tại. Tuy nhiên, do cấu trúc tương đối chính xác hơn của nó, Cách tử Bragg sợi có thể ảnh hưởng đến hiệu suất đo của chúng trong một số điều kiện bên ngoài (chẳng hạn như tác động hoặc biến dạng vật lý đáng kể có thể làm hỏng cấu trúc lưới). Tuy nhiên, trong hoàn cảnh bình thường, as long as obvious physical damage risks are avoided, the overall anti-interference ability is strong.

Cảm biến nhiệt độ sợi quang, Hệ thống giám sát thông minh, Nhà sản xuất cáp quang phân phối tại Trung Quốc