fiber optics solutions for extreme environments

ਫਾਈਬਰ ਆਪਟਿਕ ਤਾਪਮਾਨ ਸੂਚਕ, ਬੁੱਧੀਮਾਨ ਨਿਗਰਾਨੀ ਸਿਸਟਮ, ਚੀਨ ਵਿੱਚ ਵੰਡਿਆ ਫਾਈਬਰ ਆਪਟਿਕ ਨਿਰਮਾਤਾ

Fluorescent fiber optic temperature sensors have numerous advantages suitable for extreme environments:

High sensitivity: It can achieve extremely high sensitivity, which enables precise sensing of small temperature changes even in extreme environments. For example, 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, ਆਦਿ), avoiding potential hazards such as electric sparks that may be caused by power supply.
Diversity and flexibility of measurement points: By changing the number and position of fluorescent probes in the optical fiber, it is easy to achieve multi-point or distributed temperature measurement. In large-scale pipeline networks, buildings with wide coverage areas, ਆਦਿ, 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, withstanding high temperatures, high pressures, and corrosive chemical substances. Maintain the normal temperature measurement function of sensors in high-temperature, high-pressure, and highly corrosive environments such as the combustion zone of aerospace engines, around metal smelting furnaces, and inside chemical reaction vessels.
Long term stability: The combination of fluorescent substances and optical fibers has high chemical and physical stability. Under long-term and uninterrupted monitoring requirements, such as temperature monitoring of offshore oil and gas platform equipment and environmental temperature monitoring station equipment in the Arctic region, it can work stably for a long time, greatly reducing the frequency of maintenance and calibration, effectively saving costs and manpower.
High precision: 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. For example, 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, ਆਦਿ, 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. ਇਸ ਲਈ, in extreme environments with explosive hazards such as chemical and oil and gas storage, its intrinsic safety is extremely high.

Distributed fiber optic temperature sensors also have their unique advantages for extreme environments:

Insulation: Optical fibers themselves are electrically insulated, ਕੁਦਰਤੀ ਤੌਰ 'ਤੇ ਸੁਰੱਖਿਅਤ, and resistant to electromagnetic interference. This is of great significance in environmental monitoring of power systems, such as near large substations or high-voltage transmission towers. This insulation can prevent electrical accidents and ensure that temperature measurements are not affected by external electromagnetic interference, ensuring data accuracy. Distributed fiber optic temperature sensors are capable of working in environments with electromagnetic interference risks, such as temperature monitoring of power facilities in areas with frequent lightning strikes or temperature monitoring of wind and photovoltaic power generation equipment during operation.
Long distance monitoring: It can achieve distributed continuous real-time temperature monitoring over a long distance and a large range, accurately measuring the temperature value at any point along the fiber optic cable. In extreme environments with long-distance characteristics, such as temperature difference monitoring of the entire submarine fiber optic cable, temperature monitoring along multi kilometer or even tens of kilometers long oil pipelines or urban heating pipeline systems, it is possible to achieve full fiber coverage and obtain comprehensive temperature information, greatly reducing the complexity and cost of detection point layout.
Corrosion resistance: The material used to make the fiber optic core is silicon dioxide, which endows the fiber optic sensor with excellent corrosion resistance and long service life. 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, ਆਦਿ) 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, which can meet the needs of different projects and installation positions. 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. For example, in complex and diverse production scenarios in various industries such as chemical, electronic, metallurgical, pharmaceutical, ਆਦਿ, it can effectively work when measuring the thermal distribution field of large storage tanks storing flammable, ਵਿਸਫੋਟਕ, gas or other substances. Moreover, in large equipment such as boilers, generators, ਆਦਿ, 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. ਇਸਦੇ ਇਲਾਵਾ, good temperature monitoring results can be achieved in extreme scenarios such as temperature field distribution measurement in bridges, dams, ਜਹਾਜ਼, large buildings, warehouses, high-pressure vessels, tunnels, and even aircraft and spacecraft bodies.

Basic Principles and Development of Distributed Fiber Optic Sensors

The principle of distributed fiber optic temperature sensor 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. ਵਰਤਮਾਨ ਵਿੱਚ, 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, the performance of the entire distributed fiber optic temperature sensor continues to improve to better adapt to various extreme environmental measurement needs.

Fiber Bragg grating temperature sensors also have multiple advantages suitable for extreme environments:

Unique signal carrier and corresponding advantages: using reflected wavelength as the signal carrier (i.e. wavelength modulation), it is not affected by current and voltage fluctuations. Compared with traditional sensors that use current and voltage as signal carriers, such as temperature sensors based on traditional electrical measurement methods (such as metal resistance based temperature detectors) in ultra-low temperature and strong magnetic field environments, they cannot work due to the Kondo effect at ultra-low temperatures (causing a significant increase in temperature probe resistance), 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: small in size, light in weight, and easy to continuously produce multiple gratings in one optical fiber. The grating array produced is lightweight and flexible, and when combined with time-division multiplexing and wavelength division multiplexing technologies, it is very suitable as a distributed sensing element. It performs well in distributed multi-point temperature measurement of large areas or large-scale structures, such as the need to arrange numerous measurement points on the surface of the huge fuselage of an aerospace aircraft, and temperature monitoring at multiple points on the surface and inside of large superconducting equipment (maglev train superconducting components, particle accelerator superconducting components, ਆਦਿ). After embedding or pasting inside or on the surface of the structure, multi-point temperature measurement can be achieved; This feature is also beneficial for reducing the complexity and weight burden of equipment when arranging multiple sensors, 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. ਇੱਕੋ ਹੀ ਸਮੇਂ ਵਿੱਚ, 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
ਫਲੋਰੋਸੈਂਟ ਫਾਈਬਰ ਆਪਟਿਕ ਤਾਪਮਾਨ ਸੂਚਕ: Based on the principle of fluorescent fiber optic, it naturally isolates electromagnetic interference and can ensure accurate temperature measurement without being affected in extreme scenarios such as strong electromagnetic field environments, industrial plants with numerous electronic devices and complex electromagnetic environments.
Distributed fiber optic temperature sensor: Fiber optic has the fundamental characteristics of electrical insulation and immunity to electromagnetic interference. In the strong electromagnetic field area related to electricity (around substations and high-voltage transmission lines), temperature measurement data is stable, without interference or deviation, and can accurately monitor temperature in factory workshops with a large number of electrical equipment generating complex electromagnetic fields.
ਫਾਈਬਰ ਬ੍ਰੈਗ ਗਰੇਟਿੰਗ ਤਾਪਮਾਨ ਸੈਂਸਰ: Using wavelength as the signal carrier, it avoids electromagnetic interference in current and voltage, and can stably detect temperature in extreme scenarios with high-intensity electromagnetic fields (such as around large particle accelerators, near strong electromagnetic emission equipment, ਆਦਿ).
In terms of extreme environmental resistance (high temperature, ਉੱਚ ਦਬਾਅ, strong corrosion, ਆਦਿ)
ਫਲੋਰੋਸੈਂਟ ਫਾਈਬਰ ਆਪਟਿਕ ਤਾਪਮਾਨ ਸੂਚਕ: 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).
Distributed fiber optic temperature sensor: 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.
ਫਾਈਬਰ ਬ੍ਰੈਗ ਗਰੇਟਿੰਗ ਤਾਪਮਾਨ ਸੈਂਸਰ: 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
ਫਲੋਰੋਸੈਂਟ ਫਾਈਬਰ ਆਪਟਿਕ ਤਾਪਮਾਨ ਸੂਚਕ: 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. For example, 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.
Distributed fiber optic temperature sensor: 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). Moreover, 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.
ਫਾਈਬਰ ਬ੍ਰੈਗ ਗਰੇਟਿੰਗ ਤਾਪਮਾਨ ਸੈਂਸਰ: Multiple gratings can be integrated on a single optical fiber to achieve multiple measurement points. ਹਾਲਾਂਕਿ, 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, it also has great flexibility in attachment and embedding.
Cost and application popularization aspects
ਫਲੋਰੋਸੈਂਟ ਫਾਈਬਰ ਆਪਟਿਕ ਤਾਪਮਾਨ ਸੂਚਕ: It has achieved large-scale industrial production and application, with rapidly decreasing costs. Currently, it is widely used in medical diagnosis, energy management, and other fields. With the expansion of popularity and technological upgrades, there is still room for cost reduction, making it easy for new users to choose and adopt. Introducing this sensor through infrastructure renovation does not require particularly huge cost investment.
Distributed fiber optic temperature sensors have been widely used in large-scale engineering projects (such as health monitoring of large bridge structures and long-distance pipeline temperature monitoring systems) and specific industrial scenarios (such as power plants and substation monitoring). Although its technology has developed maturely, 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, ਆਦਿ. ਹਾਲਾਂਕਿ, with the promotion of technology, advances in materials, and the improvement of equipment integration, its application cost is also expected to decrease.
ਫਾਈਬਰ ਬ੍ਰੈਗ ਗਰੇਟਿੰਗ ਤਾਪਮਾਨ ਸੈਂਸਰ: 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. Moreover, 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.