scholarly journals Miniature Fiber Optic Acoustic Pressure Sensors With Air-Backed Graphene Diaphragms

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Qian Dong ◽  
Hyungdae Bae ◽  
Zhijian Zhang ◽  
Yongyao Chen ◽  
Zhongshan Wen ◽  
...  
Keyword(s):  
Acoustic Pressure ◽  
Fiber Optic ◽  
Capillary Tube ◽  
Graphene Film ◽  
Pressure Sensors ◽  
Experimental Results ◽  
Fiber Optic Sensor ◽  
Mechanical Sensitivity ◽  
Sensor Performance ◽  
Silver Composite

Graphene has been known to possess exceptional mechanical properties, including its extremely high Young’s modulus and atomic layer thickness. Although there are several reported fiber optic pressure sensors using graphene film, a key question that is not well understood is how the suspended graphene film interacts with the backing air cavity and affects the sensor performance. Based on our previous analytical model, we will show that the sensor performance suffers due to the significantly reduced mechanical sensitivity by the backing cavity. To remedy this limitation, we will, through experimental and numerical methods, investigate two approaches to enhance the sensitivity of fiber optic acoustic pressure sensors using graphene film. First, a graphene–silver composite diaphragm is used to enhance the optical sensitivity by increasing the reflectivity. Compared with a sensor with pure graphene diaphragm, graphene–silver composite can enhance the sensitivity by threefold, while the mechanical sensitivity is largely unchanged. Second, a fiber optic sensor is developed with enlarged backing air volume through the gap between an optical fiber and a silica capillary tube. Experimental results show that the mechanical sensitivity is increased by 10× from the case where the gap side space is filled. For both approaches, signal-to-noise ratio (SNR) is improved due to the enhanced sensitivity, and comsol Thermoviscous acoustics simulation compares well with the experimental results. This study is expected to not only enhance the understanding of fluid–structural interaction in sensor design but also benefit various applications requiring high-performance miniature acoustic sensors.

A fiber-optic probe and FT-NIR for onsite quality analysis of olive oils

NIR news ◽  
2018 ◽  
Vol 29 (4) ◽  
pp. 4-8 ◽  
Author(s):  
José A Adame-Siles ◽  
Francisco Sánchez-Müller ◽  
Francisco Maroto-Molina ◽  
Cecilia Riccioli ◽  
Ana Garrido-Varo ◽  
...  
Keyword(s):  
Near Infrared ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Quality Analysis ◽  
Fiber Optic Probe ◽  
Sensor Performance ◽  
Olive Oils ◽  
Decision Making Processes ◽  
Enhance Efficiency ◽  
Optic Probe

Compliance checks at reception of olive oil in bulk before unloading is an essential step for packing plants to meet quality standards and ensure traceability. Nevertheless, classic procedures based on the withdrawal of samples followed by at-line analysis need to be improved. Near-infrared spectroscopy features can make it an ideal technology to enhance efficiency and decision-making processes. This article presents a new approach whose main pillar is the automated use of a fiber-optic sensor to sample and analyse olive oils in bulk, directly in the tank before the downloading at the reception point. Moreover, a preliminary assessment of the sensor performance is also reported.

scholarly journals Simple fiber-optic sensor for simultaneous and sensitive measurement of high pressure and high temperature based on the silica capillary tube

2019 ◽  
Vol 27 (18) ◽  
pp. 25777 ◽  
Author(s):  
Haoyang He ◽  
Yi Liu ◽  
Yingying Liao ◽  
Changpeng Lang ◽  
Yan Li ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Fiber Optic ◽  
Capillary Tube ◽  
Fiber Optic Sensor ◽  
Optic Sensor ◽  
Silica Capillary

A Reflective Fiber Optic Sensor for Surface Roughness In-Process Measurement

2002 ◽  
Vol 124 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Jiancheng Liu ◽  
Kazuo Yamazaki ◽  
Yi Zhou ◽  
Sadayuki Matsumiya
Keyword(s):  
Surface Roughness ◽  
Light Intensity ◽  
Fiber Optic ◽  
Simulation Method ◽  
Experimental Results ◽  
Fiber Optic Sensor ◽  
Roughness Measurement ◽  
Surface Roughness Measurement ◽  
Optic Sensor ◽  
Sensor Probe

The paper deals with the development of a fiber optic sensor for surface roughness measurement. A new method for the calculation of reflection light intensity is proposed. By numerically counting the amount of reflection light rays from a measured surface, the relationship between the reflection light intensity and the surface roughness can be found. The simulation method is useful in understanding the effects of the sensor probe structure and the component parameters on the performance of the sensor such that an optimum sensor design can be obtained. A fiber optic sensor probe for surface roughness measurement was designed and fabricated using the results obtained by simulation. Experimental results show that the prototype sensor probe has high resolution and sensitivity for ground and milled surfaces with the roughness value (Ra) of 0.1μm∼3.2μm. The experimental results also show that the simulation method is accurate, and hence useful in designing fiber optic sensors. The simulation procedure and feasibility of the simulation method as well as the experimental results obtained from the prototype sensor probe are presented in this paper.

scholarly journals Fiber-Optic Temperature and Pressure Sensors Applied to Radiofrequency Thermal Ablation in Liver Phantom: Methodology and Experimental Measurements

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Daniele Tosi ◽  
Edoardo Gino Macchi ◽  
Alfredo Cigada
Keyword(s):  
Thermal Ablation ◽  
Rayleigh Scattering ◽  
Fiber Optic ◽  
Optical Measurement ◽  
Ex Vivo ◽  
Pressure Sensors ◽  
Fiber Optic Sensor ◽  
Tissue Temperature ◽  
Biophysical Parameters ◽  
Radiofrequency Thermal Ablation

Radiofrequency thermal ablation (RFA) is a procedure aimed at interventional cancer care and is applied to the treatment of small- and midsize tumors in lung, kidney, liver, and other tissues. RFA generates a selective high-temperature field in the tissue; temperature values and their persistency are directly related to the mortality rate of tumor cells. Temperature measurement in up to 3–5 points, using electrical thermocouples, belongs to the present clinical practice of RFA and is the foundation of a physical model of the ablation process. Fiber-optic sensors allow extending the detection of biophysical parameters to a vast plurality of sensing points, using miniature and noninvasive technologies that do not alter the RFA pattern. This work addresses the methodology for optical measurement of temperature distribution and pressure using four different fiber-optic technologies: fiber Bragg gratings (FBGs), linearly chirped FBGs (LCFBGs), Rayleigh scattering-based distributed temperature system (DTS), and extrinsic Fabry-Perot interferometry (EFPI). For each instrument, methodology forex vivosensing, as well as experimental results, is reported, leading to the application of fiber-optic technologiesin vivo. The possibility of using a fiber-optic sensor network, in conjunction with a suitable ablation device, can enable smart ablation procedure whereas ablation parameters are dynamically changed.

Hydrostatic Fiber Optic Liquid Level Sensor with position sensitive detector

Metrologiya ◽  
2020 ◽  
pp. 38-51
Author(s):  
V. N. Astapov ◽  
I. N. Kozlova
Keyword(s):  
Fiber Optic ◽  
Effective Area ◽  
Raw Material ◽  
Position Sensitive Detector ◽  
Fiber Optic Sensor ◽  
Liquid Level ◽  
Problem Solution ◽  
Sensitive Detector ◽  
Position Sensitive ◽  
Triangulation Sensor

This article presents the rationale and methodology for developing an intrinsically safe device, namely, a hydrostatic fiber optic sensor with a position-sensitive detector for monitoring the level of oil products in large-capacity tanks at oil depots and during pumping in a raw material warehouses. This device suitable for continuous monitoring of the liquid level, based on the measurement of a hydrostatic column of liquid with automatic offset of changes in the density of the liquid. Offset is carried out by means of a displacer (a fully submerged float), inside which a housing with a position-sensitive detector (PSD) is integrated. Theoretical validation of the bellows suspension usage for a displacer is given. During filling a container with a liquid whose level is measured, liquid bellows, the movement of which is recorded by an optical triangulation sensor using the reflected infrared ray incident on the bottom of the bellows. The principle of the triangulation sensor operation is based on the geometric properties of the triangles. The pulses of infrared radiation come through a fiber optic cable. In order to measure the movement of the surface (the bottom of the bellows) by measuring the movement of the reflected beam, a position-sensitive detector is used, which is located in a remote controller. In this device for the intrinsic safety problem solution, optical inputs of a fiber optic flat cable are located in the active zone of the sensor, which is connected to the optical inputs of a position-sensitive detector, operated on the principles of photoelectric effect. The light spot moving along the sensitive zone and converted by the detector into a one-dimensional signal proportional to the distance to the object. hydrostatically applies pressure over the entire effective area of the measuring

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