An active core fiber optic sensor for detecting trace H2S at high temperature using a cadmium oxide doped porous silica optical fiber as a transducer

2007 ◽  
Vol 127 (2) ◽  
pp. 471-479 ◽  
Author(s):  
T.V.S. Sarma ◽  
Shiquan Tao
Keyword(s):  
High Temperature ◽  
Optical Fiber ◽  
Fiber Optic ◽  
Cadmium Oxide ◽  
Porous Silica ◽  
Fiber Optic Sensor ◽  
Optic Sensor ◽  
Active Core ◽  
Silica Optical Fiber ◽  
Core Fiber

Sol-gel derived porous silica as a constituent material for designing optical fiber chemical sensors

2004 ◽  
Vol 828 ◽  
Author(s):  
Shiquan Tao ◽  
Joseph C. Fanguy ◽  
Lina Xu
Keyword(s):  
High Temperature ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Chemical Sensors ◽  
Fiber Optic ◽  
Sol Gel ◽  
Porous Silica ◽  
Fiber Optic Sensor ◽  
Spectrometric Method ◽  
Constituent Material

AbstractSol-gel processes were developed to prepare nano porous silica materials. The obtained porous sol-gel silica (PSGS) materials have been used as constituent materials in designing optical fiber chemical sensors. A PSGS membrane coated on the surface of an optical fiber was used as a transducer for sensing humidity level in air. A PSGS membrane doped with an ammonia indicator dye has been coated on an optical fiber to sense ammonia in air. Both of the coating based sensors are reversible and fast response. In the tested range, relative humidity (RH) in air down to 3% can be detected with the PSGS coated fiber optic sensor. The fiber optic ammonia sensor with ammonia indicator doped PSGS coating can be used to sense ammonia in air down to sub-ppm level. PSGS has also been used as a constituent material in preparing porous silica optical fibers. The obtained porous optical fibers have been used to design optical fiber chemical sensors for sensing humidity, ammonia and volatile organic compounds. A CuCl2 doped PSGS fiber has been tested for sensing ammonia in a high temperature gas sample. Ammonia in the high temperature air gas diffuses into the PSGS fiber, reversibly reacts with CuCl2 doped in the PSGS fiber to form a complex. The formed complex was detected with fiber optic spectrometric method. This sensor can detect ammonia in a high temperature (450 °C) air gas stream down 0.3 ppm. Techniques of preparing PSGS, coating PSGS on an optical fiber, making a porous optical fiber with PSGS as a constituent material will be presented. Examples of optical fiber sensors using PSGS coatings and a PSGS fiber as transducers for gas sensing are presented.

Perovskite-Type Oxide Thin Film Integrated Fiber Optic Sensor for High-Temperature Hydrogen Measurement

2009 ◽  
Vol 81 (18) ◽  
pp. 7844-7848 ◽  
Author(s):  
Xiling Tang ◽  
Kurtis Remmel ◽  
Xinwei Lan ◽  
Jiangdong Deng ◽  
Hai Xiao ◽  
...  
Keyword(s):  
Thin Film ◽  
High Temperature ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Oxide Thin Film ◽  
Optic Sensor ◽  
Perovskite Type Oxide ◽  
Perovskite Type ◽  
Hydrogen Measurement

Construction and Evaluation of the Fiber-Optic Sensor System for Chemical Vapor Detection

2008 ◽  
Vol 55-57 ◽  
pp. 509-512 ◽  
Author(s):  
M. Kittidechachan ◽  
I. Sripichai ◽  
W. Supakum ◽  
S. Thuamthai ◽  
Suppalak Angkaew ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Fiber Optic ◽  
Chemical Vapor ◽  
Fiber Optic Sensor ◽  
Sensor System ◽  
Laser Source ◽  
Vapor Concentration ◽  
Vapor Detection ◽  
Optic Sensor ◽  
Butyl Amine

The fiber optic sensor system for chemical vapor detection was desiged and constructed. The system consisted of three parts; the optic unit, the fiber-optic sensing head and the flow controlling unit. The optic unit included a He-Ne laser source which lazes a red laser into an aligned optical fiber, a photo detector, and a signal processing with computer interface controlled by the Labview® program version 7.1. The sensing head was made of a polyaniline thin film coated onto the de-cladded section of an optical fiber covered by a gas mixing cell. The concentration of measured gas was controlled by varying nitrogen gas flow rate. The nitrogen flow controller was set-up to obtain vapor concentration in the range of 0.04 to 0.40 % v/v. Vapors of hydrochloric acid (HCl) and n-butyl amine (a weak base) were used to test the performance of the sensor system. It was found that output intensity increases with an increasing HCl concentration and decreases with increasing n-butyl amine concentration. The response toward the amine vapor was faster than that of the HCl vapor (23 seconds for n-butyl amine and 72 seconds for HCl). Experiments performed at various concentrations of amine vapor (between 0.04 to 0.21 %v/v) found that a higher concentration yields faster response time.

Application of Fiber Optic BOTDA Sensor for Fire Detection in a Building

2006 ◽  
Vol 321-323 ◽  
pp. 212-216
Author(s):  
Il Bum Kwon ◽  
Chi Yeop Kim ◽  
Dae Cheol Seo
Keyword(s):  
Temperature Distribution ◽  
Optical Fiber ◽  
Fiber Optic ◽  
Smart Structures ◽  
Fire Detection ◽  
Fiber Optic Sensor ◽  
Sensor System ◽  
Real Time Processing ◽  
Optic Sensor ◽  
Electro Optic

Smart structures are to be possessed many functions to sense the external effects, such as seismic loads, temperature, and impact by some explosion, influenced on the safety of structures. This work was focused on the development of a sensing function of smart structures to get the temperature distribution on structures to detect fire occurrences. A fiber optic BOTDA (Brillouin Optical Time Domain Analysis) sensor system was developed to detect the fire occurrence by measuring the temperature distribution of a building’s exterior surfaces. This fiber optic sensor system was constructed with a laser diode and two electro-optic modulators, which made this system faster than systems using only one electro-optic modulator. The temperature distributed on an optical fiber can be measured by this fiber optic BOTDA sensor. An optical fiber, 1400 m in length, was installed on the surface of a building. Using real-time processing of the sensor system, we were able to monitor temperature distribution on the building’s surfaces, and changes in temperature distribution were also measured accurately with this fiber optic sensor.

Twin-core fiber-optic sensor for simultaneous temperature and strain measurement

1984 ◽  
Author(s):  
J. R. Dunphy ◽  
Gerry Meltz ◽  
M. M. Abou El Leil ◽  
Elias Snitzer
Keyword(s):  
Strain Measurement ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Optic Sensor ◽  
Core Fiber
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