Enzyklopädie der Faser-Bragg-Gitter-Sensortechnologie - FBG FAQ - FBG Sensor FAQ - FBG Demodulator FAQ - Analyse häufiger Anwendungsprobleme von FBG
Inhärente Nachteile von Faser-Bragg-Gittern, Herausforderungen bei der Verpackung von Faser-Bragg-Gitter-Sensoren und Prinzipien der Temperaturkompensation für Faser-Bragg-Gitter-Sensoren
This article analyzes the inherent drawbacks of fiber Bragg gratings (FBGs), which pose technical challenges in the packaging of fiber Bragg grating sensors (FBG sensors). It also introduces the accurate fiber Bragg grating temperature sensor (Bragg fiber grating thermometer) und proposes temperature compensation solutions for fiber Bragg grating stress sensors und fiber Bragg grating strain sensors developed by DCYS. The article also mentions fiber Bragg grating strings/arrays (FBGs) und serial fiber Bragg grating sensors with FBGs (serial FBG sensors ).
Im vorherigen Artikel, 'Grundprinzipien von Faser-Bragg-Gittern und Faser-Bragg-Gitter-Sensoren - Teil 2: FBG-Sensorprinzipien,' haben wir gelernt, dass Faser-Bragg-Gitter (FBGs) grundlegende physikalische Größen wie Spannung, Dehnung und Temperatur direkt messen können. Diese direkte Messung ist möglich, da die Gitterperiode (Gitterabstand) von FBGs direkt mit drei grundlegenden physikalischen Parametern zusammenhängt: Kraft (Zug- oder Druckkraft), Länge (Dehnung oder Kontraktion) und Temperatur (Erwärmung oder Abkühlung). Unter diesen Änderungen werden Kraft- und Temperaturschwankungen als Ursachen betrachtet, während Längenänderungen als Ergebnisse betrachtet werden (wie in Abbildung 1 gezeigt).
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Abbildung 1 |
Die oben genannten Schlussfolgerungen bilden die theoretische Grundlage für die Sensorik mit Faser-Bragg-Gittern (FBGs) und Faser-Bragg-Gitter-Sensoren (FBG-Sensoren). Sie stellen jedoch auch eine neue Herausforderung oder technische Schwierigkeit dar, nämlich den inhärenten Nachteil von Faser-Bragg-Gittern.
1. Nachteile von Faser-Bragg-Gittern (FBGs) und Herausforderungen bei der Verpackung von Faser-Bragg-Gitter-Sensoren (FBG-Sensoren)
The problem we face is that when using a fiber Bragg grating (FBG) und a fiber Bragg grating sensor (FBG sensor) for sensing und detection, we observe a change in the reflected wavelength (corresponding to the change in grating pitch). The challenge lies in determining whether this change is caused by force variations or temperature variations.
Solange dieses Problem nicht gelöst ist, ist es unmöglich, den Typ des verwendeten Faser-Bragg-Gitter-Sensors zu bestimmen (Faser-Bragg-Gitter-Temperatursensor, Faser-Bragg-Gitter-Spannungssensor oder Faser-Bragg-Gitter-Dehnungssensor). Darüber hinaus ist es schwierig, die Genauigkeit der Messungen von Faser-Bragg-Gitter-Sensoren zu gewährleisten.
2. Beginnen Sie mit einem genauen Faser-Bragg-Gitter-Temperatursensor
In this remarkable era, DCYS has been fortunate to stand on the shoulders of giants in multiple industries und has creatively combined the modern metallurgical pipe manufacturing industry with the fiber Bragg grating sensing industry. As a result, we have developed our own solution to address the challenge of separating temperature und stress/strain in fiber Bragg gratings (FBGs) und fiber Bragg grating sensors (FBG sensors). This solution has led to the creation of the OFSCN® capillary Seamless Steel Tube Fiber Bragg Grating Sensor series (refer to Figures 2 und 3 for the packaging structure of the fiber Bragg grating sensor).
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Abbildung 2 |
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Abbildung 3 |
Abbildung 2 shows the OFSCN® capillary Seamless Steel Tube Fiber Bragg Grating Temperature Sensor (Type 01). We can confidently state that this fiber Bragg grating temperature sensor perfectly achieves the separation of temperature and stress/strain, both in principle and in practical measurements. We will provide further details and experimental evidence in subsequent articles.
This product also offers high sensitivity, fast heat conduction, excellent accuracy, compact size, light weight, high tensile and compressive strength, high temperature resistance, corrosion resistance, water and moisture resistance, non-combustibility, and Sonstiges characteristics. It is an innovative Bragg fiber grating temperature sensor. With this product, we hope that DCYS can help advance the entire fiber Bragg grating sensing industry and contribute to its further development.
3. Prinzipien der Temperaturkompensation für Faser-Bragg-Gitter-Spannungssensoren und Faser-Bragg-Gitter-Dehnungssensoren
Abbildung 3 shows the OFSCN® capillary Seamless Steel Tube Fiber Bragg Grating Stress/Strain Sensor (Type 02). Although this product does not achieve temperature and stress/strain separation independently, it can be used in conjunction with the OFSCN® capillary Seamless Steel Tube Fiber Bragg Grating Temperature Sensor (Type 01) to address the challenge of temperature and stress/strain separation, as depicted in Figure 4.
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Abbildung 4 |
4. Konzept von Faser-Bragg-Gitter-Ketten/Arrays (FBGs) und seriellen Faser-Bragg-Gitter-Sensoren (FBG-Sensoren mit FBGs)
To better understand the previous diagram, let's first supplement some basic knowledge about fiber Bragg gratings (FBGs). One of the flexible features of fiber Bragg grating sensors is the ability to achieve multipoint sensing. In theory, we can inscribe numerous FBGs with different wavelengths in a single sensor, enabling distributed detection of one or multiple physical parameters (corresponding to the OFSCN® Capillary Seamless Steel Tube Distributed Fiber Bragg Grating Sensor).
Ein konkretes Beispiel zeigt Abbildung 5, die eine Faser mit neun FBGs unterschiedlicher Wellenlängen darstellt. Diese Anordnung ermöglicht die gleichzeitige Messung an neun verschiedenen Punkten.
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Abbildung 5 |
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Abbildung 6 Abbildung 6 zeigt die Wellenlängenverteilung eines achtkanaligen Faser-Bragg-Gitter-Arrays (FBGs) auf einem optischen Spektrumanalysator. |
5. Temperaturkompensation für Faser-Bragg-Gitter-Sensoren
Returning to the example in Abbildung 4, we use two OFSCN® Capillary Seamless Steel Tube Fiber Bragg Grating Sensors, Sensor 1 and Sensor 2, with different wavelengths. Sensor 1 is sensitive to both temperature and stress/strain, while Sensor 2 is only sensitive to temperature. They are placed in the same environment, with the same temperature. For Sensor 1, the change in wavelength includes the influence of both temperature and stress/strain. However, we already know its temperature accurately (from Sensor 2), so we can subtract the temperature's impact on the wavelength change, leaving only the effect of stress/strain (calculation details can be found in the formula: ΔλＢ ＝λＢ（１－Ｐｅ）Δε＋λＢ（αｆ－ξ）ΔＴ).
In dieser Sensorkonfiguration wird Sensor 1 zu einem genau kalibrierten Faser-Bragg-Gitter-Spannungssensor und Faser-Bragg-Gitter-Dehnungssensor (dieser Berechnungsprozess wird als Temperaturkompensation für Faser-Bragg-Gitter-Sensoren bezeichnet).
The OFSCN® Capillary Seamless Steel Tube Fiber Bragg Grating Temperature Sensor can also be used for temperature compensation in Sonstiges applications, such as fiber Bragg grating vibration sensors, fiber Bragg grating shape sensors, fiber Bragg grating gas sensors, and fiber Bragg grating pressure sensors.
Based on the above discussion, the OFSCN® Capillary Seamless Steel Tube Fiber Bragg Grating Sensors produced by DCYS successfully achieve the separation of temperature and stress/strain, overcoming the inherent drawbacks of fiber Bragg gratings. The key lies in the fact that the OFSCN® Capillary Seamless Steel Tube Fiber Bragg Grating Temperature Sensor provides accurate temperature measurement unaffected by stress/strain. How does DCYS achieve this? The principles and mysteries will be revealed in the Weiter article. Stay tuned!
Our philosophy is: 'OFSCN®, make optical fiber stronger!'
DCYS is a professional manufacturer of high accuracy fiber bragg grating temperature sensor, providing high accuracy FBG temperature sensor temperature measurement accuracy principle, temperature compensation principle, temperature measurement inaccuracy solutions and Sonstiges information; high accuracy FBG temperature sensor brand 'OFSCN'.