sensore di temperatura ottico-INNO

Panoramica di Sensore di temperatura a fibra ottica fluorescente

Il sensore di temperatura a fibra ottica fluorescente è un tipo di sensore che utilizza le caratteristiche dei materiali fluorescenti per la misurazione della temperatura. È costituito da fibre ottiche multimodali e da un oggetto fluorescente (film) montato sopra. Quando una sostanza fluorescente viene eccitata dalla luce di una certa lunghezza d'onda (spettro di eccitazione), emette energia di fluorescenza dopo l'eccitazione. Dopo che l'eccitazione è stata annullata, La persistenza dell'afterglow fluorescente dipende da fattori quali le caratteristiche della sostanza fluorescente e la temperatura ambientale. Questa fluorescenza eccitata di solito decade in modo esponenziale, dove la costante di tempo di decadimento è la durata della fluorescenza o il tempo di post-luminescenza della fluorescenza (ns). A diverse temperature ambiente, il decadimento del bagliore residuo della fluorescenza varia, quindi la temperatura ambiente può essere determinata misurando la durata del bagliore residuo della fluorescenza. La sua tecnologia principale risiede nelle sostanze fluorescenti e nei corrispondenti algoritmi di simulazione. Il materiale fluorescente che misura la temperatura viene calcinato ad alta temperatura 1200 gradi, che ha una lunga durata, caratteristiche di lavoro stabili e affidabili, adatto per la produzione industriale su larga scala, e può essere ampiamente applicato nel campo industriale. Un tipico fluorescente sensore di temperatura in fibra ottica include una fonte di luce, fibra ottica, materiale fluorescente, e spettrometro. La sorgente luminosa genera luce di eccitazione di una determinata lunghezza d'onda, che viene trasmesso al materiale fluorescente attraverso una fibra ottica. The fluorescent material absorbs the excitation light and emits a specific wavelength of fluorescent light signal, which is then transmitted back to the spectrometer for detection through the optical fiber. Quando la temperatura cambia, the flash characteristics (fluorescence intensity or wavelength) of the fluorescent material change, and the temperature value can be determined by measuring the intensity or wavelength of the flash signal.

Vantaggi di Sensore di temperatura a fibra ottica fluorescente

1. In termini di precisione
I materiali fluorescenti sono particolarmente sensibili ai cambiamenti di temperatura, which enables fiber optic fluorescent temperature sensors to have high measurement accuracy and meet the needs of many measurement scenarios that require high temperature accuracy. Per esempio, precise control of reaction temperature in scientific experiments and monitoring of patient temperature in the medical field require accurate temperature measurement, and this sensor can effectively undertake such tasks. In certain specific application scenarios, its accuracy can reach a precision level of ± 0.05 ℃ o anche superiore.

2. Caratteristiche della risposta
The sensor has a fast response speed and can monitor temperature changes in real time and respond immediately. This feature is particularly useful in scenarios with rapidly changing temperatures, such as overload monitoring in power systems and the need to promptly detect temperature changes in areas where heat is suddenly generated during industrial production processes to prevent potential safety hazards.

3. Distributed measurement capability
It is possible to monitor the temperature of multiple locations simultaneously through a single optical fiber. It can be imagined that if temperature monitoring is carried out at multiple points inside a large engineering structure such as bridges, Tunnel, and so on., only one fiber optic cable is needed to complete the task. Questo non solo consente di risparmiare sui costi, but also enables real-time and comprehensive judgment of the temperature status of the overall structure in different parts. Inoltre, it can measure temperature on the same optical fiber and may also have other functions such as data transmission, greatly improving the efficiency of fiber optic systems.

4. Anti interference characteristics
Not affected by interference signals, able to work normally in complex electromagnetic environments. In some industrial environments with strong electromagnetic fields (such as power substations) or inside electrical equipment (come i quadri, and so on.), traditional temperature sensors (come le termocoppie, Resistenze termiche, and so on.) generate induced currents in the electromagnetic field due to the measurement probes and wires made of their own metal materials. This current, a causa dell'effetto pelle e dell'effetto delle correnti parassite, possono aumentare la propria temperatura, interferire con i risultati della misurazione della temperatura, o rendere le misurazioni instabili. Il sensore di temperatura a fibra ottica fluorescente utilizza la trasmissione in fibra ottica di segnali ottici, che sono completamente insensibili alle interferenze elettromagnetiche, garantendo una misurazione accurata e stabile.

5. Stabilità a lungo termine
I materiali fluorescenti hanno una forte durata e stabilità, consentendo ai sensori di mantenere stabilità ad alte prestazioni per lunghi periodi di utilizzo. In situazioni in cui è richiesto il monitoraggio ininterrotto della temperatura a lungo termine, come durante esperimenti di ricerca scientifica a lungo termine o monitoraggio della temperatura durante il ciclo di vita di alcune apparecchiature industriali chiave, può garantire una raccolta dati di temperatura stabile e accurata per lungo tempo senza frequenti calibrazioni o sostituzioni del sensore.

6. Adattabilità della temperatura ambientale
Adatto per un'ampia gamma di temperature ambientali, effective measurements can be taken from as low as minus Baidu to as high as several hundred degrees Celsius. It can play a role in both low-temperature special experimental environments (such as temperature measurement related to ultra-low temperature superconducting experiments) and high-temperature industrial processing environments (such as metal smelting, and so on.).

7. Flexibility and Scalability
Fluorescent materials for sensors can be selected and designed according to actual needs to meet the requirements of various specific application fields. As long as the fluorescent material is adjusted or replaced, it can adapt to different application scenarios. Per esempio, in campo medico, targeted designs can be made for different human body parts or special environments of different medical devices.

Comparison between Fluorescent Fiber Optic Temperature Sensor and Other Optical Temperature Sensors

1. Comparison with infrared temperature sensors
Differences in working principles
Fluorescent fiber optic temperature sensor is based on the temperature fluorescence characteristics of fluorescent materials, and achieves temperature measurement by measuring the lifetime or intensity of fluorescent afterglow, as well as changes in wavelength; Infrared temperature measurement utilizes the principle that the infrared radiation energy of an object changes with temperature, and obtains temperature information by measuring the infrared radiation intensity of the target.
Per esempio, when measuring the temperature of a metal block that is being heated, a fluorescent fiber optic temperature sensor needs to place the optical fiber close to or connected to the surface of the metal block (with contact and non-contact installation methods), and use the changes in the fluorescent substance inside to measure the temperature; The infrared thermometer directly receives the infrared radiation emitted by the metal block for temperature measurement without the need for contact with the metal block.
Differences in accuracy and sensitivity
Infrared temperature measurement is greatly affected by factors such as target surface emissivity, temperatura ambiente, e la distanza di misurazione, and its accuracy and sensitivity are relatively unstable. For some medium and low temperature measurement scenarios, there may be significant errors; The measurement accuracy of fluorescent fiber optic temperature sensors is relatively higher, because the sensitivity of fluorescent materials to temperature allows them to detect temperature changes more accurately, and in the mid to low frequency range, fluorescent fiber optic temperature sensors can maintain good measurement performance.
Per esempio, in a temperature monitoring scenario inside a chemical reaction vessel with small temperature fluctuations and high precision measurement requirements, the accuracy of the fluorescent fiber temperature sensor can be controlled within a small range, while the accuracy of infrared temperature measurement is difficult to guarantee due to factors such as the surrounding environment of the reaction vessel and the optical properties of the vessel itself.
Adapt to the differences in scenarios
Infrared temperature measurement is suitable for non-contact and rapid temperature measurement of surface temperature in non low temperature scenarios, but it has a significant impact on the temperature reading of bright or polished metal surfaces, and can only measure the external temperature of objects, making it inconvenient to measure the internal temperature when there are obstacles; Fluorescent fiber optic temperature sensors can not only be used for surface temperature measurement, but also for measuring internal temperature through appropriate methods such as probe insertion. They will not affect the measurement accuracy of some special materials due to interference from optical properties and have strong universality.
Per esempio, la misurazione della temperatura a infrarossi può ottenere rapidamente una temperatura superficiale approssimativa per determinare preliminarmente la situazione di dissipazione del calore quando si misura la temperatura superficiale dei dissipatori di calore dei chip dei circuiti elettronici. Tuttavia, se è necessario misurare la temperatura interna del chip o la temperatura alla radice del chip con dissipatori di calore, non è sufficiente. I sensori di temperatura a fibra ottica fluorescenti possono ottenere misurazioni ad alta precisione di chip con dissipatori di calore se la sonda a fibra ottica può raggiungere l'interno del chip o se è progettata una sonda adatta.

2. Confronto con PT100
Differenze nei principi di funzionamento e negli ambienti applicabili
PT100 utilizza la caratteristica del valore di resistenza del metallo platino che cambia con la temperatura per misurare la temperatura, based on the principle of resistance; The fluorescent fiber optic temperature sensor is based on the principle of fluorescence. PT100 is a contact type sensor.
In an environment with electromagnetic interference, the metal components of PT100 can conduct interference such as pulse group interference, interferenze in radiofrequenza, picchi, and so on., causing the thermostat to malfunction or be damaged; Sensori di temperatura a fibra ottica fluorescente, due to the use of fiber optic transmission of optical signals, are less affected by electromagnetic interference and can be used in high voltage and strong electromagnetic interference environments, such as transformer interiors, quadri, and so on.
Per esempio, in the temperature monitoring inside the distribution cabinet of a high-voltage substation, if PT100 is used, due to the electromagnetic interference generated by various electromagnetic devices inside the distribution cabinet, the temperature measured by PT100 may have significant errors or even damage the sensor due to interference; But using fluorescent fiber optic temperature sensors can accurately and stably measure temperature.
Differences in accuracy and stability
During the use of PT100, as time and environmental temperature change, the resistance of the metal may also be affected by its own and other surrounding physical and chemical factors, resulting in slight changes in the resistance temperature relationship, which affects the accuracy and stability of the measurement; After special treatment, the fluorescent material of the fluorescent fiber temperature sensor has stronger stability and is not easily affected by external factors (except temperature). Its accuracy is more advantageous than PT100 in complex environments.

3. Comparison with Fibra ottica distribuita sistema di misurazione della temperatura

Different working principles
Fluorescence fiber temperature measurement is based on the principle of fluorescence lifetime afterglow to measure temperature. It requires fixing the fluorescence fiber on the surface of the measured object and exciting it with a light source to measure the fluorescence lifetime and other parameters emitted by the fluorescence fiber. Allora, the temperature of the measured object is calculated based on these parameters; Distributed fiber optic temperature measurement utilizes the inherent characteristics of optical fibers to measure temperature through internal reflection and scattering. It usually involves laying optical fibers around the object being measured and exciting the fibers with light sources such as lasers or LEDs. Allora, based on the scattering and reflection characteristics of the internal optical signals of the fibers, the temperature of the object being measured is calculated.
Measurement application scenarios focus on different aspects
Fluorescent fiber optic temperature measurement is usually suitable for measurement occasions that require insulation and high voltage resistance in electromagnetic interference environments, come i quadri ad alta tensione, Trasformatori, microwave electromagnetic environments, and so on. Because it can stably measure through the characteristics of fluorescent materials in such environments and does not interfere with equipment, and so on; Distributed fiber optic temperature measurement is suitable for situations that require long-distance, continuo, and high-precision temperature monitoring of the object being measured, such as temperature monitoring of building structures such as oil and gas pipelines, Tunnel, Ponti, and so on., because it can use scattering reflection to monitor continuous temperature changes over long distances along the fiber optic cable.

How to choose the best fluorescent fiber optic temperature sensor

1. Consider the requirements of the application field
Adapt to special environmental requirements
When there are special situations such as strong electromagnetic/radio frequency interference, infiammabilità, esplosività, corrosione, and so on. in the working environment, fluorescent fiber optic temperature sensors have unique advantages. Per esempio, in the petrochemical industry, there are complex chemical substances that may corrode sensors. It is very important to choose sensors that can resist corrosion and work safely in this potentially explosive safety risk environment. The fiber probe and fiber itself of the fluorescent fiber optic sensor can withstand high voltage and some chemical corrosion without generating ignition sources such as electric sparks, thus meeting the temperature measurement requirements of this special environment. The temperature measurement environment of downhole equipment in oil extraction belongs to this category.
If the working environment is limited by small installation space, it is necessary to choose fiber optic probes and fibers of appropriate size. Fluorescent fiber optic temperature sensors can be made into smaller probes, and the fibers have strong flexibility and plasticity, making them easier to install in small spaces compared to other traditional sensors, such as temperature monitoring of heating parts inside some microelectronic devices.
Alta precisione, sensibilità, e requisiti di stabilità
In alcuni esperimenti di ricerca scientifica, such as high-precision physics experiments and biochemistry experiments, the accuracy control of temperature is very strict, so it is necessary to choose fluorescent fiber temperature sensors with high accuracy, such as sensor products with accuracy of ± 0.05 ℃ or ± 0.1 °C. Allo stesso tempo, if the experiment lasts for a long time, such as several days or even weeks for certain biochemical reactions, the stability of the sensor and the sensitivity of the measurement (which can quickly and accurately capture small temperature fluctuations) are also crucial. This requires the selection of sensors that use high-quality fluorescent materials and have good signal processing systems to ensure that the measurement will not produce errors due to environmental temperature fluctuations or material fluorescence performance degradation.
In alcune industrie manifatturiere di fascia alta, come la lavorazione di componenti nel settore aerospaziale, le corrispondenti apparecchiature di monitoraggio della temperatura richiedono anche un'elevata precisione e stabilità a lungo termine dei sensori.

2. Determinare il metodo di misurazione e l'intervallo di misurazione
Determinare il tipo di sensore in base ai punti di misurazione
Se ci sono meno punti di misurazione (solitamente inferiore a 50), è possibile utilizzare un sensore di temperatura a fibra ottica fluorescente a punto singolo. I sensori a punto singolo hanno costi relativamente bassi in questa situazione e sono facili da disporre e installare in modo flessibile per ogni singolo punto di misurazione. Per esempio, il monitoraggio della temperatura di diverse apparecchiature sperimentali speciali in un piccolo laboratorio richiede solo l'installazione separata dei sensori per questi dispositivi.
Quando ce ne sono più di 50 punti di misurazione, il costo complessivo dell'utilizzo di un sensore a punto singolo sarà molto elevato, e il cablaggio sarà molto complesso. In questo caso, a distributed fiber optic temperature sensor system or other more suitable methods for large-scale multi-point measurement can be considered (if the overall accuracy requirements are not so high and a certain degree of substitution is allowed). There are hundreds or thousands of servers in a large data center room, and if temperature monitoring is required for some server locations, a large number of measurement points are needed. If single point sensors are used, the cost-effectiveness is extremely low.

Intervallo di temperatura di misurazione

Select based on the actual measured temperature range. The temperature measurement range of fiber optic sensors is divided into four sections:- 40°C- +80°C；- 40°C- +250°C；- 40C – +400°C；+ 20C -+600 °C (medico). Per esempio, a sensor with a temperature range of -40 °C -+80 ℃ may be sufficient for ordinary indoor temperature monitoring; But for high-temperature scenarios such as industrial furnaces or aircraft engine testing, sensors that can measure high temperature ranges such as -40 °C -+400 ℃ or even higher are needed.
3. Probe performance related
The working type of the probe
For immersion probes, they can be used to measure the temperature of solids, liquidi, e gas, come la misurazione della temperatura nei serbatoi di liquidi industriali. This probe has undergone special treatment, and its optical fiber has strong strength and toughness, che può resistere alla corrosione chimica nei serbatoi di liquidi. Per esempio, measuring the temperature of reactants (which may be a mixture of liquid, solido, e gas) in a chemical reactor is very suitable.
Contact type probes are specifically designed to measure the temperature of object surfaces, such as temperature monitoring for high-voltage equipment such as dry-type transformers, Quadro elettrico ad alta tensione, e sbarre ad alta tensione. Può essere ben fissato alla superficie del dispositivo per trasmettere con precisione la temperatura all'interno del sensore per la misurazione.
Le sonde mediche sono progettate appositamente per le misurazioni nelle scienze della vita, con sonde piccole e sottili che, se abbinato a dispositivi di demodulazione dedicati, può raggiungere velocità di risposta elevate e precisione molto elevata. Utilizzato in campo medico, come scenari di rilevamento della temperatura ad alta precisione per piccoli tessuti o aree locali all'interno del corpo umano.
La dimensione della sonda e la lunghezza della fibra ottica
Seleziona la dimensione della sonda (diametro) e la lunghezza della fibra in base ai requisiti dell'oggetto e dell'ambiente di misurazione. Il diametro della sonda è solitamente di 0,5 mm; 0.5 – 1millimetro； 2.3millimetro； 3.2millimetro, and so on. La lunghezza standard della fibra è 2M, ma la maggior parte può personalizzare la lunghezza della fibra della sonda e la lunghezza del cavo di prolunga in fibra in base alle esigenze. Se lo spazio di misurazione è stretto, it may be necessary to choose a smaller diameter probe and customize the fiber length according to the actual installation space. To measure temperature at small gaps in electronic components, a small diameter probe should be used and the fiber length should be customized according to the depth of the gap; If measuring temperature inside large mechanical structural components, a longer fiber length is required to extend to the core area that needs to be measured.

4. Other performance parameters of the equipment
Precisione e risoluzione
When precision and resolution are required, the temperature measurement accuracy of fiber optic sensors is usually divided into five levels: ± 0.05 °C; ±0,1℃； ±0,3℃； ±0,5°C； ± 1 °C. If high-precision temperature measurement is required, such as internal temperature monitoring in certain high-precision optical instruments or high-precision temperature monitoring or cell preservation devices in medicine, sensors with high accuracy and resolution, such as sensors with an accuracy of ± 0.05 ℃ or ± 0.1 °C, need to be selected; If the precision requirements are not so high, sensors for indoor temperature monitoring with an accuracy of ± 1 ℃ can also meet the requirements.
sampling frequency
The sampling frequency of fiber optic sensor temperature measurement system is usually divided into four levels:= 10Hz； 20Hz； 1kHz； 200kHz. When monitoring rapidly changing temperature scenarios, such as monitoring the hot spot temperature inside a high-speed motor, a high sampling frequency (per esempio. 1kHz or 200kHz) is required to capture temperature changes in a timely manner to prevent overheating emergencies; For some scenarios with relatively slow temperature changes, such as ordinary indoor temperature monitoring, selecting a sampling frequency of 10Hz or 20Hz can meet the requirements.
Signal output interface
L'uscita del segnale è divisa in uscita analogica e uscita digitale. In an automated industrial control system, it is more suitable to choose sensors with digital output interfaces for direct data acquisition and analysis through devices such as computers, so that digital signal transmission and processing can be carried out without signal conversion; If some traditional instrument control systems may only support the reception of analog signals, then the analog output interface can be directly connected to the instrument equipment for display and simple control.
Installation form of detector
Signal demodulator mainly comes in handheld portable and fixed forms, with or without display. Fixed products include industrial standard DIN rail installation, Scheda PCB, desktop ordinario, and standard industrial cabinet type. If it is a temporary outdoor use to detect the temperature of several points inside a large device, it can be handheld, portatile, flexible to move, and easy to operate and arrange for detection; If monitoring the long-term stability and operating temperature of a large production line equipment, it is necessary to choose a fixed and suitable industrial environment, such as DIN rail installation or cabinet installation, which can be easily connected to the production line automation monitoring system.

5. Consider cost-effectiveness
Ciò è dovuto al fatto che vari tipi di sensori in fibra ottica sono prodotti tecnologici relativamente nuovi con prezzi generalmente elevati, gli utenti solitamente devono fare una scelta tra prestazioni/funzionalità del prodotto e prezzo. Dapprima, determinare la base di riferimento dei requisiti minimi di prestazione, quindi confrontare fattori come il prezzo tra le linee di prodotti che possono soddisfare questo requisito di base.

Per esempio, se esistono tre marche diverse di sensori di temperatura a fibra ottica fluorescente, Il prodotto A ha una precisione di ± 0.1 °C, alta risoluzione, e buona capacità anti-interferenza, con un prezzo di 1000 yuan; La precisione del prodotto B è ± 0.3 °C, leggermente inferiore nella capacità anti-interferenza, e il prezzo è 800 yuan; La precisione del prodotto C è ± 0.5 °C, che sostanzialmente soddisfa i requisiti anti-interferenza dell'ambiente di utilizzo. Il prezzo è 600 yuan. If precision and anti-interference are highly valued and the budget is sufficient, product A can be chosen; If the precision requirement is not extremely high and the budget is limited, then C product is also an option.

Application Case of Fluorescent Fiber Optic Temperature Sensor

1. In the field of power grid
Temperature monitoring is crucial in the power grid. Fluorescent fiber optic temperature sensors have the characteristics of high accuracy and fast response, which can accurately monitor temperature changes in industrial production processes. Per esempio, in equipment such as switchgear and transformers, fluorescent lifetime fiber optic temperature sensors can monitor the temperature of critical connection points, detect temperature anomalies in a timely manner, and prevent overheating and arc accidents. Traditional temperature sensors may read inaccurately in such high voltage environments due to electromagnetic interference, but fluorescent fiber optic sensors are not affected by such interference and have high reliability. Inoltre, high temperatures in transformers may cause insulation material aging and lead to faults. Fluorescent lifetime fiber optic temperature sensors can be installed in the oil or near the windings of transformers to monitor temperature, ensuring normal operation and extending their service life.

2. Campo medico
In magnetic resonance imaging (MRI) Tecnologia, superconducting magnets need to be cooled to extremely low temperatures. Fluorescent lifetime fiber optic temperature sensors can be used to monitor the performance of cooling systems and ensure that magnets are at the correct temperature. Due to the presence of strong magnetic fields in the MRI environment, traditional electronic temperature sensors may be subject to interference or damage, while fiber optic sensors do not have these issues. Inoltre, fluorescent lifetime fiber optic sensors can also be used in clinical medicine, such as monitoring patient temperature during temperature monitoring or thermal therapy, to ensure safe and effective treatment. Due to their high precision and fast response, they are suitable for situations that require strict temperature control.

3. Gestione energetica
In the energy industry, fluorescent fiber optic temperature sensors can be used to monitor the operating temperature of power equipment and systems, ensuring the safe and efficient utilization of energy.

In sintesi, fluorescent fiber optic temperature sensors play an important role in multiple fields due to their high precision, risposta rapida, stabilità a lungo termine, e resistenza alle interferenze elettromagnetiche. Con il continuo sviluppo della tecnologia, their application prospects will become even broader.