Sensor suhu serat optik INNO ,sistem pemantauan suhu.
1. Prinsip Pemantauan Suhu Serat Optik
Sensor suhu serat optik adalah sensor canggih yang mengukur perubahan suhu dengan memanfaatkan efek optik. Ini memanfaatkan sifat unik dari serat optik, seperti sensitivitas termal dan efek kisi Bragg. Prinsip dasarnya adalah menggunakan sifat optik serat optik untuk mencerminkan perubahan suhu lingkungan dengan mengukur parameter sinyal optik (seperti intensitas cahaya, fase, dll.) dalam serat. Berikut ini adalah beberapa metode pemantauan suhu serat optik yang umum berdasarkan prinsip yang berbeda:
1.1: Berdasarkan prinsip variasi amplitudo cahaya:
Pada komponen sensor suhu tipe serat optik, diameter inti dan indeks bias serat berubah seiring suhu, menyebabkan cahaya yang merambat di dalam serat menyebar ke luar karena jalur yang tidak rata, mengakibatkan perubahan amplitudo cahaya. Misalnya, dalam beberapa struktur serat khusus, perubahan suhu dapat menyebabkan perubahan distribusi material atau karakteristik struktur di dalam serat, resulting in changes in the scattering of light during propagation, and thus causing changes in the amplitude of light. By detecting these amplitude changes, informasi suhu dapat diperoleh.
Based on the principle of interference: In the instrument, light from the signal fiber is mixed with a stable reference beam. Due to the influence of the measured parameters (seperti suhu) on the signal fiber, fase perubahan sinyal optik yang merambat, resulting in interference between the two light beams. Pada prinsipnya, a suitable phase detector can detect small changes, sementara penghitung garis dapat mendeteksi perubahan besar. This utilizes the interference characteristics of light, converting the influence of temperature on the phase of optical signals in optical fibers into detectable interference phenomena, thereby achieving temperature monitoring.
1.2: Based on the principle of Raman scattering effect:
The basic principle of Sistem Penginderaan Suhu Serat Optik Terdistribusi (DTS) is based on the optical time domain reflectometry (OTDR) principle of fiber optic and the Raman scattering effect of fiber optic. Pulsa laser berinteraksi dengan molekul serat, menghasilkan berbagai fenomena hamburan seperti hamburan Rayleigh, Hamburan Brillouin, dan penyebaran Raman. Select the Raman scattering that is most sensitive to temperature changes when selecting the system reference signal. The mechanism of fiber optic temperature measurement is based on the backward Raman scattering effect, which obtains temperature information by analyzing the Raman scattering light signal. Because the intensity of Raman scattering light has a specific relationship with temperature, temperature changes can cause changes in Raman scattering intensity. By measuring the changes in Raman scattering intensity, nilai suhu dapat ditentukan.
1.3: Based on the principle of Bragg fiber Bragg grating:
In quasi Serat Optik Terdistribusi teknologi pengukuran suhu, a representative solution is a temperature measurement system with multiple fiber Bragg gratings connected in series. Several Bragg fiber gratings with different center wavelengths are formed by exposure and etching along the longitudinal direction of the optical fiber through ultraviolet radiation. Each Bragg fiber grating is power total reflection for a specific wavelength of light. When the ambient temperature of the fiber Bragg grating changes, the wavelength of the reflected signal from the grating will also change. Inject a beam of broad-spectrum light containing multiple wavelengths into an optical fiber, and the beam passes through a series of fiber Bragg gratings. Each grating reflects a monochromatic light signal corresponding to its wavelength, and temperature changes are reflected by detecting changes in the reflected light wavelength.
1.4: Based on the principle of fluorescence radiation:
In fluorescence radiation fiber temperature sensing technology, a fluorescent substance is coated on the end of the fiber, and the temperature value of the measured point can be obtained by measuring the decay time of fluorescence energy and utilizing the temperature correlation of the intrinsic afterglow time of the fluorescent substance. The afterglow time of fluorescent substances changes with temperature, and this characteristic is used for temperature measurement. Its applicable temperature range is -50~200 ℃, with an accuracy of about ± 1 °C, and it is commonly used for temperature measurement inside electrical equipment.
1.5: Principle of Light Absorption/Transmission Characteristics Based on Gallium Arsenide Crystals:
Gallium Arsenide Fiber Temperature Measurement Technology embeds gallium arsenide crystal material into the far end of the fiber as a temperature probe, and injects incident light into the near end device of the fiber. When the sensor light source emits multi wavelength incident light and radiates onto the gallium arsenide crystal, the gallium arsenide crystal material will absorb different wavelengths of incident light at different temperatures, and the unabsorbed wavelengths of light will be reflected back to the device. By analyzing the spectrum of reflected light, the temperature parameters at the probe can be obtained. The advantage of this sensor is that it obtains the probe temperature through absolute spectral measurement rather than temperature change measurement, so it does not involve on-site calibration. The probe has good universality, and the sensing distance can exceed 500m. The light source life and long-term stability of online detection can exceed 30 Tahun. Namun, the cost of gallium arsenide fiber is relatively high.
2. Method of Fiber Optic Temperature Monitoring
According to different application scenarios, fiber optic temperature measurement technology can be divided into the following categories:
2.1: Pengukuran suhu titik:
Fluorescence radiation fiber temperature sensing technology: a fluorescent substance is coated on the end of the fiber, and the temperature value of the measured point is obtained by measuring the decay time of fluorescence energy and utilizing the temperature correlation of the intrinsic afterglow time of the fluorescent substance. Suitable for temperature range of -50~200 ℃, with an accuracy of about ± 1 °C, currently mainly used for temperature measurement inside electrical equipment. Ia memiliki ciri-ciri berukuran kecil, integrasi yang mudah, kinerja yang andal, anti interferensi elektromagnetik, kinerja isolasi yang baik, Instalasi yang nyaman, dan jaringan yang fleksibel.
2.2 Gallium Arsenide Fiber Optic Temperature Measurement Technology:
Embedding gallium arsenide crystal material into the far end of the optical fiber as a temperature probe, injecting incident light into the near end device of the fiber. When the sensor light source emits multi wavelength incident light and radiates onto the gallium arsenide crystal, the gallium arsenide crystal material absorbs different wavelengths of incident light at different temperatures, and the unabsorbed wavelengths of light are reflected back to the device. The temperature parameters at the probe are obtained by analyzing the spectrum of the reflected light. Its advantages are that the probe temperature is obtained through absolute spectral measurement, without on-site calibration, the probe has good universality, the sensing distance can exceed 500m, the light source life and online detection long-term stability exceed 30 Tahun, but the cost is relatively high.
2.3 Pengukuran terdistribusi kuasi:
Fiber Bragg Grating Series Temperature Measurement System: Through ultraviolet radiation along the longitudinal direction of the fiber, several Bragg fiber gratings with different center wavelengths are formed by exposure and etching. Each Bragg fiber grating is power total reflection for a specific wavelength of light. Multiple Bragg fiber gratings are sequentially connected in series in the direction of fiber propagation to form a spatially discrete quasi spatial distribution temperature measurement system. Injecting broadband light into an optical fiber, when the beam passes through a fiber Bragg grating, each grating reflects a monochromatic light signal corresponding to its wavelength. When the ambient temperature of the fiber Bragg grating changes, the wavelength of the grating reflected signal will change. Its probe has a small volume, the optical path can be appropriately bent, it is resistant to electromagnetic radiation, and easy to telemetry. Namun, the mechanical strength of the fiber Bragg grating is low, and it is easily damaged under complex working conditions, which requires the reliability of the sensor. Lagipula, the sensitivity of wavelength demodulation is a problem, and the wavelength drift of reflected light caused by a temperature rise of tens of degrees does not exceed 1nm.
2.4 Pengukuran terdistribusi penuh:
Sistem Pengukuran Suhu Serat Terdistribusi (DTS) Based on Raman Scattering Effect: Utilizing the Optical Time Domain Reflector (OTDR) principle of optical fibers and Raman scattering effect. Laser pulses interact with fiber molecules to generate various scattering phenomena such as Raman scattering, and temperature is measured based on the Raman scattering effect. This system can be implemented by deploying a monitoring device and a sensing fiber, and the monitoring cost per unit fiber length decreases with the increase of sensing distance. It is currently a highly promising engineering temperature measurement solution. It can achieve temperature measurement in single point, multi-titik, and continuous areas, and can serve as a medium for temperature measurement and transmission simultaneously. It has anti electromagnetic interference ability, ketahanan korosi, kinerja isolasi yang baik, flexible installation methods, can be linked with fire protection, sistem alarm, dll. It can also remotely transmit data, view and control remotely, and has advantages such as data analysis and fault point troubleshooting.
3. Application case of fiber optic temperature monitoring
3.1 Penerapan dalam Pembangunan Tenaga Komunikasi:
Problem solved: The communication room has dense equipment and high security requirements. Begitu terjadi kebakaran, it will cause the entire communication network to be paralyzed, requiring real-time monitoring of the room temperature. And with the rapid development of 5G technology, communication rooms are rapidly being built and expanded, resulting in a sudden increase in the number and power of equipment in the rooms. Traditional electronic temperature measurement methods have disadvantages such as limited temperature measurement points, complex installation of transmission cables, and are not conducive to maintenance and management.
Specific implementation plan: Install a distributed Sistem pemantauan suhu serat optik (such as FGT series) on the equipment and lines in the computer room to achieve real-time temperature monitoring, analisis tren, remote accurate detection of accidents, peringatan dini, alarm and other functions. The core part of the system mainly consists of a local client, host pengukuran suhu serat optik, kabel optik penginderaan suhu, dan perangkat lunak pengukuran suhu. Misalnya, temperature sensing optical fibers enter each cabinet from below and measure the temperature inside the cabinet by circling around the front and back of the cabinet; The temperature measuring optical fiber is laid in an S-shape along the cable tray on the surface of the cable tray for temperature monitoring of the cable tray; The temperature measuring optical fiber is laid along the underground tunnel cable route on the surface of the cable for temperature monitoring of the tunnel cable; Upload to the local client and monitoring center client via TCP/IP protocol, and the client can display real-time temperature information of each cabinet through monitoring software. Based on the obtained real-time temperature, draw a temperature cloud map of the computer room; When an abnormal high temperature alarm occurs at a certain location in the computer room, the temperature measurement host transmits the alarm information to the alarm system through the RS485 serial protocol for corresponding fire extinguishing treatment.
Nilai aplikasi: In addition to regional alarms, early warning positioning can also locate and set the temperature of alarm points; Real time temperature display can accurately determine the development trend of fire accidents and provide data basis for firefighting; It has the advantages of safety and reliability (sensitivitas tinggi, tidak ada interferensi elektromagnetik, passive real-time monitoring, isolasi listrik yang baik, tahan ledakan, combined with fixed and differential temperature alarms, tidak ada alarm palsu), Instalasi mudah (fiber optic anti tension, anti impact, diameter luar kecil, fleksibilitas yang baik, volume kecil, ringan, can be wound and installed on the surface of the testing area in a straight or snake shape), efficient use (pemantauan jarak jauh, detection and signal transmission can be completed by one optical cable, all set at the terminal, the entire system is simple and reliable, and the operation and maintenance workload is minimal), and ultra long service life (the built-in constant temperature circuit system and advanced microcomputer electro-optical switch greatly improve the service life of the equipment, with a service life of more than 15 Tahun).
3.2 Applications in the field of transportation:
In road tunnels, fiber optic sensors can be used to monitor parameters such as temperature and humidity inside the tunnel, detect dangerous situations such as fires and floods in a timely manner, and trigger alarm systems to ensure the safety of vehicles and passengers. Fiber optic sensors also have important application value in the construction of intelligent transportation systems and vehicle safety monitoring, such as monitoring the temperature of key parts of vehicles to ensure the safety and reliability of vehicle operation.
3.3 Application in power plants:
Compared with the traditional temperature sensing cable, the optical fiber temperature monitoring system is progressiveness. Di pembangkit listrik, fiber optic temperature sensors can monitor the temperature of equipment in real time during operation, such as temperature monitoring of large equipment such as generators and transformers. They can detect abnormal situations such as overheating in a timely manner, thereby avoiding equipment failures and ensuring the normal operation of power plants.
4. Recommended Fiber Optic Temperature Monitoring Equipment
FJINNO’s IF-C sistem pengukuran suhu serat optik fluoresensi:
Kemampuan anti-interferensi fluoresensi dan metode pengukuran: Ia memiliki karakteristik menolak interferensi elektromagnetik, dan serat optik sebagai media transmisi sinyal tidak terpengaruh oleh interferensi elektromagnetik, memastikan pemantauan suhu yang akurat di dekat peralatan listrik bertegangan tinggi. Mendukung pengukuran multi-titik, beberapa antarmuka pengukuran dapat diatur pada pemancar suhu serat optik neon untuk mencapai pemantauan suhu multi-titik.
5. Bagaimana memilih solusi pemantauan suhu serat optik yang sesuai
5.1: Pertimbangkan persyaratan skenario pengukuran:
Persyaratan kisaran suhu: Teknologi pemantauan suhu serat optik yang berbeda dapat diterapkan pada rentang suhu yang berbeda. Misalnya, teknologi penginderaan suhu serat optik radiasi fluoresensi cocok untuk kisaran suhu -50~200 ℃. Jika suhu lingkungan yang akan diukur rendah atau tinggi, a customized fiber optic temperature monitoring scheme that can cover this temperature range is required.
5.2: Measurement points and areas:
If it is a single point temperature measurement, such as measuring temperature at a key part inside an electrical equipment, point based temperature measurement methods such as fluorescence radiation fiber temperature sensing technology or gallium arsenide fiber temperature measurement technology are more suitable; If temperature monitoring is required for continuous areas or multiple points, such as cabinets, Baki kabel, and underground tunnel cables in communication power buildings, distributed fiber optic temperature monitoring systems (DTS) are more suitable for temperature monitoring in multiple areas.
5.3: Consider the performance characteristics of the sensor:
Akurasi dan stabilitas: In some scenarios that require high temperature measurement accuracy, such as real-time temperature monitoring during surgical procedures in the medical field, high-precision fiber optic temperature sensors need to be selected.
5.4: Sensor response speed:
In some scenarios where rapid temperature changes are required, such as fire alarm systems, sensors need to have a fast response speed to detect abnormal temperature increases in a timely manner and issue alarms. The response speed of different fiber optic temperature sensors varies and needs to be selected according to specific application scenarios.
5.5: Consider cost factors:
Equipment cost: The manufacturing process of high-performance fiber optic temperature sensors is complex and costly, which limits their large-scale application. Misalnya, gallium arsenide fiber optic sensors have many advantages, but their cost is relatively high. In the case of limited budget, it is necessary to comprehensively consider equipment costs and choose a cost-effective fluorescent fiber temperature monitoring solution.
5.6: Installation and maintenance costs:
The complexity of installing different fiber optic temperature monitoring solutions varies, and installation costs may also differ. Misalnya, di Sistem pemantauan suhu serat optik terdistribusi in the communication power building, the laying method of fiber optic cables, installation and commissioning of equipment will all affect the installation cost. Pada waktu bersamaan, maintenance costs also need to be considered, such as the service life of the equipment, whether it is prone to malfunctions, and the difficulty of repairing after a malfunction. Some devices with self diagnosis and remote maintenance functions may have higher equipment costs, but in terms of long-term maintenance costs, they may be more cost-effective.
Sensor suhu serat optik, Sistem pemantauan cerdas, Produsen serat optik terdistribusi di Cina
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