Fiber M fiber optic temperature sensors

Fiberoptisk temperatursensor, Intelligent övervakningssystem, Tillverkare av distribuerad fiberoptik i Kina

Application of Fiber M Fiber Temperature Sensor for Temperature Monitoring in High Temperature and Harsh Environments

1、 Common models of Fiber M fiber optic temperature sensors

Fiber M fiber temperature sensors may have multiple models to suit different application scenarios. In the current market, some fiber optic temperature sensor models have their own unique performance parameters and applicable ranges. Till exempel, model AF28- OPTIC3000X2 (stock number: M241812）1， It uses multimode optical fiber to provide high voltage isolation, and its casing is made of stainless steel material, which can meet the installation requirements of industrial environments. The interface of this model of sensor is ST fiber optic interface, which is easy to install and has high anti-interference performance. Övergripande, it is very suitable for operation in harsh environments. Its temperature measurement range is -55 °C -+125 °C, with a temperature measurement error of less than or equal to 0.5 ℃ in the full range. The temperature measurement resolution is ± 0.1 °C, the temperature measurement cycle is 45 Sekunder, the probe temperature range is -100 °C -+260 °C, the fiber length is less than or equal to 50m (multimode fiber), the interface method is ST interface, the battery life is 4.5 years, the operating temperature is -40 °C -+80 °C, and the probe size is 8 (diameter) mm × 200 (length) mm. Ytterligare, there is the AF28-optic3000 (library number: M178113) model fiber optic temperature sensor 2, which has a temperature accuracy of ± 0.5 °C, a SC fiber optic interface, a temperature measurement range of -40 °C -+125 ℃ or -40-+200 °C (user selectable), a temperature resolution of 12 bits (0.0625 °C), and a temperature measurement speed of 10 seconds or 45 Sekunder (user selectable). These different models can monitor temperature for different operating conditions under their respective parameters.

2、 Characteristics and requirements of temperature monitoring in high temperature and harsh environments

（1） Characteristics of temperature monitoring in high temperature and harsh environments
Environmental complexity
In high-temperature and harsh environments, there are often multiple complex factors involved. Till exempel, around some industrial furnaces, in addition to high temperatures, there may also be pollutants such as dust and corrosive gases. Near the furnace of a steel smelting plant, a large amount of dust particles are emitted into the surrounding environment along with the hot air, which may adsorb onto the temperature sensor and interfere with its normal operation. Meanwhile, with the chemical reactions during the metallurgical process, corrosive gases such as sulfur dioxide are produced, posing a risk of corrosion to temperature sensors.
Leakage and volatilization of chemical raw materials are common in high-temperature chemical production environments. Till exempel, after the leakage of acidic or alkaline chemical raw materials, the acidity and alkalinity of the surrounding environment will change, which has varying degrees of impact on the shell material and internal components of temperature sensors, and may lead to problems such as corrosion of the sensor shell and internal circuit short circuits.
Large temperature variation amplitude
The temperature fluctuation range in high-temperature environments can be very large. Taking the engine testing environment in the aerospace field as an example, the temperature rapidly rises from room temperature to thousands of degrees Celsius during engine start-up and operation. At the combustion chamber of the engine, the temperature can reach around 2000-3000 °C, while outside the engine body, the temperature may be close to room temperature. Such a huge temperature difference places high demands on the adaptability of temperature monitoring equipment.
In some high-temperature kilns, the temperature inside the kiln needs to be precisely controlled between several hundred degrees and over a thousand degrees during ceramic firing. From the preheating stage of the kiln to different stages of firing, the temperature rise and stability need to be strictly monitored, with temperature changes ranging from tens of degrees Celsius to thousands of degrees Celsius, and high-precision measurement needs to be maintained under such large changes.
There are interfering factors present
High temperature environments are usually accompanied by strong electromagnetic field interference. In the welding workshop for electrical equipment production, welding equipment generates strong electromagnetic fields during operation. Till exempel, during arc welding, the current intensity is high, and the generated electromagnetic field can interfere with the communication lines of ordinary electronic temperature sensors, affecting the accuracy of their data transmission. For fiber optic temperature sensors, although they have a certain resistance to electromagnetic interference, they also need to deal with possible interference from other electromagnetic sources in this strong electromagnetic field environment.
In some special high-temperature environments such as near nuclear reactors, in addition to high temperatures and nuclear radiation, there will also be strong magnetic fields. This strong magnetic field may alter the working state of magnetic field sensitive components in some sensors. If the design of temperature sensors does not fully consider this factor, measurement errors can easily occur.

（2） Requirements for temperature monitoring in high temperature and harsh environments
High temperature resistance
Sensors must be able to withstand extreme temperatures in high-temperature environments. If the sensor itself is not resistant to high temperatures, it is easily damaged in high-temperature environments. Till exempel, in a glass melting plant, the temperature inside the furnace can reach up to around 1600 °C, and sensors need to be directly or indirectly exposed to such high temperature environments. Their materials must be able to maintain stable physical and chemical properties at this temperature. This requires the structural materials of the sensor, such as the housing and internal sensing elements, to be made of high-temperature special materials. Till exempel, using high-temperature resistant materials such as ceramics and high-temperature alloys as external protective covers for sensors or as carriers for internal key sensing components.
high reliability
Due to the difficulty of equipment maintenance in high temperature and harsh environments, temperature sensors need to have high reliability. This means that the probability of sensor failure during long-term operation is very low, and it can continuously and stably measure temperature. Till exempel, in scientific research near deep-sea hydrothermal vents, sensors may need to work continuously for months or even years in high-temperature, high-pressure, and highly corrosive underwater environments. The temperature of the underwater hydrothermal fluid there can exceed 300 °C. If the sensors frequently malfunction, it will not only lead to the loss of research data, but may also cause huge economic losses and safety risks in some special scientific research facilities. So the design and manufacturing process of sensors need to be extremely precise, and the internal circuit or optical path structure must undergo strict stability testing.
high-precision
In high-temperature and harsh environments, many industrial production processes require extremely high precision in temperature control. Taking the photolithography process in semiconductor chip manufacturing as an example, even small temperature changes can affect the chemical reaction rate of photoresist and the accuracy of chip patterns. This process requires temperature error control within ± 1 ℃ in an environment of several hundred degrees Celsius. So temperature sensors need to be able to provide high-precision measurements to ensure product quality in production or experimentation. This requires the measurement principle and calibration algorithm of the sensor to be very accurate. Till exempel, fiber optic temperature sensors use optical principles to improve temperature measurement accuracy through precise wavelength detection or light intensity measurement.
Good anti-interference ability
As mentioned earlier, there are various interference factors in high-temperature and harsh environments. Sensors need to have good anti-interference ability to address these issues. Till exempel, in the high-temperature processing environment of RF heating equipment, RF signals can interfere with surrounding electronic devices. Sensors should be able to accurately obtain temperature information under strong radio frequency interference. For fiber optic temperature sensors, they have a natural advantage in resisting electromagnetic interference, but their design should also avoid the influence of other interference sources, such as using a special fiber optic protective layer to resist light leakage and the mixing of external interference light, while optimizing the internal signal processing circuit to improve the filtering ability of interference signals.

3、 Application case of Fiber M fiber optic temperature sensor in high temperature and harsh environment

Petrochemical industry
In the refining units of petrochemicals, there are numerous high-temperature reaction vessels and pipelines. Till exempel, in the distillation process of crude oil, the internal temperature of the distillation tower can reach 300-400 °C. Fiber M fiber optic temperature sensors can be installed inside the reactor or outside the pipeline to monitor temperature in real-time. Due to its corrosion resistance, high temperature resistance, and electromagnetic interference resistance, it can work stably for a long time in environments filled with oil and gas, high temperatures, and corrosion risks. By accurately monitoring temperature, the distillation process of crude oil can be better controlled, improving the quality and yield of petroleum products. If traditional electronic temperature sensors are used, the oil and gas environment may pose a risk of explosion, and electronic components are easily corroded and damaged. Som kontrast till detta, fiber optic temperature sensors have higher safety and reliability.
Aerospace field
In the testing and operation monitoring of aircraft engines, the temperature around the turbine blades inside the engine is extremely high. Till exempel, at the outlet of the combustion chamber of a high-performance jet engine, the gas temperature can exceed 2000 °C. Fiber M fiber optic temperature sensors can measure temperature near the blades at such high temperatures, providing accurate temperature data for engine performance evaluation and optimization. Due to the complexity of the operating environment of aerospace equipment, including high-speed airflow, strong electromagnetic radiation, etc., the small size, high anti-interference ability, and high temperature resistance of fiber optic sensors make them ideal temperature monitoring devices. In the manufacturing process of composite material structures for aircraft, the drying and curing processes need to be carried out in a high-temperature environment. Fiber optic temperature sensors can accurately monitor the temperature to ensure the quality of composite materials.
metallurgical industry
During the smelting process in a steel furnace, the temperature at which the metal inside the furnace melts can reach 1500-1600 °C. Fiber M fiber optic temperature sensors can adapt to such high temperature environments and monitor the temperature inside the furnace in real-time. Due to the presence of a large amount of dust, vibration, and electromagnetic interference in the smelting workshop, the non-contact measurement method, anti-interference ability, and high temperature resistance of fiber optic sensors enable them to work stably. Accurate temperature monitoring helps to control chemical reactions in the steelmaking process and improve the quality of steel. During the metal rolling process, the surface temperature of the high-temperature rolling mill also needs to be precisely controlled. Fiber optic temperature sensors can be installed near the rolling mill to provide temperature data for optimizing the rolling process.