fiber optics solutions for extreme environments-INNO

Capteurs de température fluorescents à fibre optique have numerous advantages suitable for extreme environments:

Haute sensibilité: It can achieve extremely high sensitivity, which enables precise sensing of small temperature changes even in extreme environments. Par exemple, in some scientific research scenarios or precision industrial control processes that are extremely sensitive to temperature changes, high sensitivity ensures measurement accuracy.
Not affected by electromagnetic interference: Based on fluorescent optical fibers for temperature measurement, it is not affected by electromagnetic interference from the surrounding environment. In industrial equipment monitoring under strong electromagnetic fields, temperature measurement of large substation equipment, or special scientific research sites with complex electromagnetic radiation environments, this advantage ensures the reliability of temperature measurement data, while traditional metal probe sensors may cause measurement errors due to electromagnetic interference.
Remote measurement capability: The transmission distance of optical fiber can reach tens of meters without affecting measurement accuracy. In some dangerous extreme environments, such as near high-temperature furnaces and nuclear radiation environments, sensors can be placed at measurement points through long-distance optical fibers, and operators can collect and monitor data from a safe distance; This is also very suitable for difficult to access scenarios such as measuring the temperature of volcanic lava and measuring the water temperature near deep-sea geothermal vents.
No need for power supply (fiber optic cables themselves do not require power supply): The main source of energy is the light source, which is safe and convenient to use in environments that require explosion-proof or isolated power supply (such as oil and gas extraction sites, chemical raw material storage warehouses, and other flammable and explosive places, mines, etc.), avoiding potential hazards such as electric sparks that may be caused by power supply.
Diversité et flexibilité des points de mesure: En changeant le nombre et la position des sondes fluorescentes dans la fibre optique, it is easy to achieve multi-point or distributed temperature measurement. In large-scale pipeline networks, buildings with wide coverage areas, etc., probes can be set up at multiple key locations according to demand for comprehensive temperature monitoring, increasing the flexibility and applicability of the system.
Corrosion resistance and high temperature resistance: Fiber optic materials have excellent corrosion resistance and high temperature resistance, and can be used in harsh environments, résister à des températures élevées, hautes pressions, et substances chimiques corrosives. Maintenir la fonction normale de mesure de la température des capteurs à haute température, à haute pression, et environnements très corrosifs tels que la zone de combustion des moteurs aérospatiaux, autour des fours de fusion des métaux, et à l'intérieur des cuves de réaction chimique.
Stabilité à long terme: La combinaison de substances fluorescentes et de fibres optiques présente une stabilité chimique et physique élevée. Sous exigences de surveillance à long terme et ininterrompue, comme la surveillance de la température des équipements des plates-formes pétrolières et gazières offshore et des équipements des stations de surveillance de la température environnementale dans la région arctique, cela peut fonctionner de manière stable pendant longtemps, réduisant considérablement la fréquence de maintenance et d’étalonnage, économisant efficacement les coûts et la main d'œuvre.
Haute précision: Fluorescent substances respond quickly and have good repeatability to temperature, making measurement results more accurate in both rapidly changing temperature fields (such as temperature fluctuations in combustion reactions) and long-term stable temperature measurement requirements, ensuring high-precision data output.
Fast data transmission speed: Fiber optic transmission of data is extremely fast, especially important in extreme environmental systems that require rapid response. Par exemple, temperature monitoring at the moment of rocket engine ignition, high-speed data transmission can provide timely feedback on temperature information for timely decision-making and adjustment; Real time or almost real-time temperature monitoring can be achieved.
Easy integration and automation: The fluorescence fiber optic temperature measurement system can be easily integrated with existing computer systems and automation equipment, facilitating the automation and intelligence of temperature monitoring. In some modern automated production factories, remote unmanned monitoring stations, etc., intelligent temperature management can be easily integrated into existing systems.
Good electrical insulation and explosion resistance: The fiber optic sensor used for fluorescence fiber optic temperature measurement is an electrical insulator that is non-conductive. Even in flammable and explosive environments, it will not generate electric sparks or static electricity, which can cause accidents. Donc, in extreme environments with explosive hazards such as chemical and oil and gas storage, its intrinsic safety is extremely high.

Capteurs de température distribués à fibre optique ont également leurs avantages uniques pour les environnements extrêmes:

Isolation: Les fibres optiques elles-mêmes sont isolées électriquement, intrinsèquement sûr, et résistant aux interférences électromagnétiques. Ceci est d'une grande importance dans la surveillance environnementale des systèmes électriques., comme à proximité de grandes sous-stations ou de pylônes de transmission haute tension. Cette isolation peut prévenir les accidents électriques et garantir que les mesures de température ne sont pas affectées par des interférences électromagnétiques externes., garantir l'exactitude des données. Fibre optique distribuée les capteurs de température sont capables de fonctionner dans des environnements présentant des risques d'interférences électromagnétiques, comme la surveillance de la température des installations électriques dans les zones où la foudre est fréquente ou la surveillance de la température des équipements de production d'énergie éolienne et photovoltaïque pendant le fonctionnement.
Surveillance longue distance: Il peut réaliser une surveillance continue et distribuée de la température en temps réel sur une longue distance et une large plage., mesurer avec précision la valeur de la température à tout moment le long du câble à fibre optique. Dans des environnements extrêmes avec des caractéristiques longue distance, comme la surveillance des différences de température de l'ensemble du câble à fibre optique sous-marin, surveillance de la température le long d'oléoducs de plusieurs kilomètres, voire de dizaines de kilomètres de long, ou de systèmes de canalisations de chauffage urbain, il est possible d'obtenir une couverture complète de la fibre et d'obtenir des informations complètes sur la température, réduisant considérablement la complexité et le coût de la disposition des points de détection.
Résistance à la corrosion: Le matériau utilisé pour fabriquer le noyau de la fibre optique est le dioxyde de silicium., ce qui confère au capteur à fibre optique une excellente résistance à la corrosion et une longue durée de vie. In highly corrosive marine environments, industrial wastewater discharge pipelines, and underground oil and gas pipelines, a large amount of corrosive media (such as seawater, acidic and alkaline solutions, etc.) are densely distributed. Distributed fiber optic temperature sensors can measure temperature stably for a long time without being eroded.
Strong flexibility: Optical fibers have excellent flexibility and flexible installation positions, qui peut répondre aux besoins de différents projets et positions d'installation. In environments with complex spatial layouts (such as small and irregular installation spaces for instruments and equipment inside spacecraft, and complex tunnel scenes in large water conservancy projects), optical fibers can be bent and arranged according to the actual spatial requirements, making it easier for sensors to accurately measure in extreme environments that are difficult to plan and layout. Temperature measurement in narrow spaces such as car engine compartments and airplane wings can also leverage this feature.
Obtaining multiple points of information at once: By measuring the entire fiber area in one go, a one-dimensional distribution map of the measured area can be obtained. By setting a special framework for the fiber (such as framing it into a grating shape), the two-dimensional and three-dimensional distribution of the measured area can also be determined. In large chemical storage tanks and buildings, it is necessary to conduct three-dimensional temperature field distribution detection (such as detecting the temperature distribution at different heights and areas in a large warehouse, using a three-dimensional fiber optic network to transmit and receive and measure the temperature at different locations), and overall temperature detection of the internal structure of large bridges, which can obtain multi-point and overall temperature information. This advantage is very obvious and can efficiently understand the temperature status of the entire monitoring space.
Suitable for various complex and extreme environments: Distributed fiber optic temperature sensors can adapt to various extreme environments. Par exemple, in complex and diverse production scenarios in various industries such as chemical, électronique, métallurgique, pharmaceutical, etc., it can effectively work when measuring the thermal distribution field of large storage tanks storing flammable, explosif, gas or other substances. De plus, in large equipment such as boilers, générateurs, etc., it is difficult to install conventional sensors due to their complex structure, or conventional sensors cannot be approached due to strong electromagnetic interference, or the cost of point by point measurement is too high to be practical. Distributed fiber optic temperature sensors can play a prominent role in these extreme environments where traditional sensors are not suitable. En outre, good temperature monitoring results can be achieved in extreme scenarios such as temperature field distribution measurement in bridges, barrages, navires, grands bâtiments, entrepôts, high-pressure vessels, tunnels, and even aircraft and spacecraft bodies.

Basic Principles and Development of Distributed Fiber Optic Sensors

The principle of distributed capteur de température à fibre optique is to use the Raman scattering principle of fiber optic. When the temperature of a certain part of the fiber optic changes, the scattered light is affected. Through high-speed signal acquisition and data processing technology, the location of the disturbance can be accurately located and real-time temperature alarm information can be provided. At the beginning of its development, it started with Rayleigh scattering systems based on optical time domain reflectometry (OTDR), and went through Raman scattering systems based on OTDR and Brillouin scattering systems based on OTDR. This development process greatly improved the temperature measurement accuracy and range. À l'heure actuelle, research on optical frequency domain reflectometry (OFDR) technology is also constantly deepening. Although there is still some way to go in terms of industrial practicality, it is still the development direction of distributed fiber optic temperature sensor technology. With the development, les performances de l'ensemble du capteur de température à fibre optique distribué continuent de s'améliorer pour mieux s'adapter aux divers besoins de mesure environnementale extrême.

Capteurs de température à réseau de Bragg à fibre présentent également de multiples avantages adaptés aux environnements extrêmes:

Support de signal unique et avantages correspondants: en utilisant la longueur d'onde réfléchie comme support de signal (c'est à dire. modulation de longueur d'onde), il n'est pas affecté par les fluctuations de courant et de tension. Par rapport aux capteurs traditionnels qui utilisent le courant et la tension comme supports de signal, tels que des capteurs de température basés sur des méthodes de mesure électriques traditionnelles (tels que les détecteurs de température basés sur la résistance métallique) dans des environnements à très basse température et à fort champ magnétique, ils ne peuvent pas fonctionner en raison de l'effet Kondo à des températures ultra-basses (provoquant une augmentation significative de la résistance de la sonde de température), Hall effect under strong electromagnetic fields, and magnetoresistance effect (causing strong interference to the readings of most electronic components). Fiber Bragg grating temperature sensors completely avoid this drawback and can perform temperature measurements normally. This characteristic of using wavelength as a signal also has stability that matches its optical method. Even in complex optical interference environments or light source fluctuations, it can still detect wavelength drift caused by temperature changes relatively stably, thus enabling accurate temperature measurement.

Small and lightweight, suitable for distributed multi-point measurement: de petite taille, léger, and easy to continuously produce multiple gratings in one optical fiber. The grating array produced is lightweight and flexible, et lorsqu'il est combiné avec les technologies de multiplexage temporel et de multiplexage par répartition en longueur d'onde, il est très approprié comme élément de détection distribué. Il fonctionne bien dans la mesure distribuée de la température multipoint de grandes surfaces ou de structures à grande échelle, comme la nécessité de disposer de nombreux points de mesure à la surface de l'immense fuselage d'un avion aérospatial, et surveillance de la température en plusieurs points à la surface et à l'intérieur des grands équipements supraconducteurs (composants supraconducteurs du train maglev, composants supraconducteurs d'accélérateur de particules, etc.). Après encastrement ou collage à l'intérieur ou à la surface de la structure, une mesure de température multipoint peut être réalisée; Cette fonctionnalité est également bénéfique pour réduire la complexité et le poids de l'équipement lors de la configuration de plusieurs capteurs., and has irreplaceable advantages for some cutting-edge applications that require strict weight requirements, such as sensor loads in aerospace exploration equipment.
Strong resistance to electromagnetic interference and corrosion: This is a common advantage of the fiber optic sensor family. This sensor can be widely used in extreme environments, whether it is for monitoring equipment temperature in high-temperature and high electromagnetic interference areas such as metal smelting factories, or for detecting temperature in some marine ship electrical equipment due to corrosion risks and electrical interference in the surrounding salt spray and humid environment. Stable operation can also be achieved in special extreme environments such as nuclear power, where there is strong electromagnetic radiation and potential corrosion risks (such as the presence of corrosive atmospheres in nuclear islands due to special chemical substances), such as temperature monitoring of external cooling system pipelines of nuclear reactors or heat monitoring of some electrical equipment inside nuclear power plants.
Sensitivity and response speed advantages: Fiber Bragg grating temperature sensors based on phase sensitive detection can achieve sub millikelvin level ultra-high sensitivity, which means that they can detect even small temperature changes (such as weak temperature fluctuations near absolute zero, temperature changes in extremely micro research environments such as biological cells), making them suitable for precise measurement of small temperature changes. En même temps, it has a fast response time and can provide timely and accurate temperature data feedback in extreme scenarios where rapid temperature changes occur, such as changes in the temperature field around the detonation shock wave generated at the moment of an explosion experiment or sudden temperature changes on the surface of the irradiated object under high-energy laser irradiation. It also has broad application prospects in fields such as biomedical imaging, microfluidics, nanotechnology, which require extremely high reaction speed and measurement accuracy.

Comparison of the advantages of fiber optics solutions in extreme environments

Anti electromagnetic interference capability
Capteur de température à fibre optique fluorescente: Based on the principle of fluorescent fiber optic, il isole naturellement les interférences électromagnétiques et peut garantir une mesure précise de la température sans être affecté dans des scénarios extrêmes tels que des environnements à forts champs électromagnétiques, installations industrielles comportant de nombreux appareils électroniques et des environnements électromagnétiques complexes.
Capteur de température à fibre optique distribué: La fibre optique possède les caractéristiques fondamentales d’isolation électrique et d’immunité aux interférences électromagnétiques.. Dans la zone de fort champ électromagnétique lié à l’électricité (autour des sous-stations et des lignes de transport à haute tension), les données de mesure de la température sont stables, sans interférence ni déviation, et peut surveiller avec précision la température dans les ateliers d'usine avec un grand nombre d'équipements électriques générant des champs électromagnétiques complexes.
Capteur de température à réseau de Bragg en fibre: Utiliser la longueur d'onde comme support de signal, il évite les interférences électromagnétiques en courant et en tension, and can stably detect temperature in extreme scenarios with high-intensity electromagnetic fields (such as around large particle accelerators, near strong electromagnetic emission equipment, etc.).
In terms of extreme environmental resistance (haute température, haute pression, forte corrosion, etc.)
Capteur de température à fibre optique fluorescente: The fiber optic material is corrosion-resistant and high-temperature resistant, and can penetrate deep into industrial furnaces at high temperatures for temperature measurement up to several hundred degrees Celsius; Work normally in environments with corrosive chemicals, such as chemical reaction vessels and acid storage tanks; Suitable for temperature monitoring in high-pressure environments (such as temperature monitoring near high-pressure hot springs in deep sea).
Capteur de température à fibre optique distribué: The fiber optic material is corrosion-resistant silicon dioxide, which can continuously monitor temperature in corrosive environments of chemical wastewater pipelines and around underground pipelines in saline alkali areas for decades of service life; Effective in monitoring the temperature along large high-temperature steam transmission pipelines in scenarios where high-temperature oil generates heat and pressure in long-distance oil pipelines; It can also be used in scenarios such as aircraft and spacecraft bodies that require temperature monitoring while experiencing high-altitude pressure changes.
Capteur de température à réseau de Bragg en fibre: With its miniaturized integrated design, it can be attached to the surface of high-temperature components (for monitoring the surface temperature of aviation turbine engine blades) for measurement; Using fiber Bragg grating sensors made of special materials to solve high temperature and ultra-high temperature measurement (such as sapphire fiber Bragg grating sensors that can measure high temperatures up to 1600 ℃); Temperature measurement can also be carried out on outdoor electrical equipment in harsh marine climate environments with corrosion risks (external motor temperature of offshore wind power generation equipment).

Measurement dimensions and flexibility
Capteur de température à fibre optique fluorescente: By adjusting the arrangement of the fluorescent probe, point to multipoint measurement can be achieved, thereby meeting the temperature measurement needs in different spaces and flexible layout requirements. It can also balance small-scale local temperature monitoring and large-scale distributed point temperature monitoring. Par exemple, when arranging temperature monitoring points for different production line equipment in a factory building, the position of fluorescent probes can be freely set according to the distribution of equipment to create or adjust the temperature monitoring layout.
Capteur de température à fibre optique distribué: The entire fiber optic line can be regarded as the sensing area, which can complete long-distance continuous measurement at once. It has natural distributed measurement characteristics, especially can easily form a fiber optic network for temperature monitoring in two-dimensional or even three-dimensional areas (such as three-dimensional warehouses and multi story buildings). De plus, the flexibility of optical fibers allows for installation positions to be unrestricted, and can be arranged between channels or equipment of different shapes and directions according to specific environments to obtain temperature values.
Capteur de température à réseau de Bragg en fibre: Multiple gratings can be integrated on a single optical fiber to achieve multiple measurement points. Cependant, compared to the above two, the density of measurement points per unit fiber length can theoretically be higher. Through wavelength division multiplexing and time-division multiplexing technology, the temperature of each grating point can be measured in time or simultaneously. It is more suitable for fields with precise spatial layout (such as narrow internal space of optical instruments and biomedical micro samples requiring multi-point accurate temperature measurement), and due to its lightweight and flexibility, il présente également une grande flexibilité de fixation et d'intégration.
Aspects du coût et de la vulgarisation des applications
Capteur de température à fibre optique fluorescente: Il a réalisé une production et une application industrielles à grande échelle, avec des coûts en baisse rapide. Actuellement, il est largement utilisé dans le diagnostic médical, gestion de l'énergie, et d'autres domaines. Avec l'expansion de la popularité et les mises à niveau technologiques, il est encore possible de réduire les coûts, ce qui permet aux nouveaux utilisateurs de choisir et d'adopter facilement. L’introduction de ce capteur dans le cadre de la rénovation des infrastructures ne nécessite pas d’investissement particulièrement important.
Les capteurs de température distribués à fibre optique ont été largement utilisés dans des projets d'ingénierie à grande échelle (tels que la surveillance de l'état des grandes structures de ponts et les systèmes de surveillance de la température des pipelines longue distance) et scénarios industriels spécifiques (tels que les centrales électriques et la surveillance des sous-stations). Bien que sa technologie se soit développée avec maturité, it is hindered in the popularization of some small or cost sensitive projects due to relatively high initial investment in measurement hosts and supporting equipment, fiber optic laying, etc.. Cependant, with the promotion of technology, advances in materials, and the improvement of equipment integration, its application cost is also expected to decrease.
Capteur de température à réseau de Bragg en fibre: It is widely used in high-end equipment manufacturing fields such as aerospace and large ship manufacturing, and also has a certain proportion of micro applications in biomedical research. Due to the limitations of fiber Bragg grating technology, especially the preparation technology of special materials such as sapphire fiber, which is mastered in a small number of units and has high costs, such as complex preparation processes and special grating writing conditions, the overall cost is high. De plus, many high-end applications still rely on imported components. If we want to apply them in general industrial scenarios or large-scale promotion of basic monitoring fields like the previous two, there are still significant cost barriers.