摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
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A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber.In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
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Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper present...
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Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper presents an approach where the fire sensor itself, when heated by nearby fire, generates electrical energy to power a radio transmitter. Presented energizing fire sensor is environmentally friendly and can be mass produced at a very low cost. Upon activation the sensor produces enough power necessary to operate most standard radio transmitters depending on what communication system is chosen for operation. The fire detector unit can be deployed from either helicopter or manually from the ground. The sensor can be designed to activate itself at different temperatures to suit different climate zones. Rough guidelines are given for estimation of attenuation of radio wave propagation in forest areas in order to predict maximum transmit distance.
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摘要 :
Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper present...
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Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper presents an approach where the fire sensor itself, when heated by nearby fire, generates electrical energy to power a radio transmitter. Presented energizing fire sensor is environmentally friendly and can be mass produced at a very low cost. Upon activation the sensor produces enough power necessary to operate most standard radio transmitters depending on what communication system is chosen for operation. The fire detector unit can be deployed from either helicopter or manually from the ground. The sensor can be designed to activate itself at different temperatures to suit different climate zones. Rough guidelines are given for estimation of attenuation of radio wave propagation in forest areas in order to predict maximum transmit distance.
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摘要 :
Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper present...
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Placing fire detectors in a forest is usually associated with powering problems since the sensors do not have access to external power supply and a periodical change of internal batteries is an undesired option. This paper presents an approach where the fire sensor itself, when heated by nearby fire, generates electrical energy to power a radio transmitter. Presented energizing fire sensor is environmentally friendly and can be mass produced at a very low cost. Upon activation the sensor produces enough power necessary to operate most standard radio transmitters depending on what communication system is chosen for operation. The fire detector unit can be deployed from either helicopter or manually from the ground. The sensor can be designed to activate itself at different temperatures to suit different climate zones. Rough guidelines are given for estimation of attenuation of radio wave propagation in forest areas in order to predict maximum transmit distance.
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摘要 :
In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fouriertransform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main prin...
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In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fouriertransform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main principle of this spectrometer is that measured collected and collimated optical radiation passes through a linear array or matrix of optical Fabry-Perot interferometers. Each interferometer is placed in front of and close to each element of the array detector. By processing the signal the spectrum of the optical radiation can be extracted. This design does not require intermediate optics between interferometer and array detector and allows for a reliable and extremely compact construction. Production cost can be low when a simple wedge type interferometer is integrated with existing array or matrix detectors, e.g. CCD camera. One other benefit is that the shape of the interferometer determines whether the spectrometer is suitable for measuring wide spectra radiation or has the ability to discriminate optical coherent radiation. Experimental results achieved for VIS and NIR range of spectra are promising. The principals of this design can be used for a variety of applications besides as a spectrometer. For example warning systems for lasers and restricted coherency sources and also filtering of optical signals and for measuring the spectral content working in a wide spectral range.
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摘要 :
In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main pri...
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In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main principle of this spectrometer is that measured collected and collimated optical radiation passes through a linear array or matrix of optical Fabry-Perot interferometers. Each interferometer is placed in front of and close to each element of the array detector. By processing the signal the spectrum of the optical radiation can be extracted. This design does not require intermediate optics between interferometer and array detector and allows for a reliable and extremely compact construction. Production cost can be low when a simple wedge type interferometer is integrated with existing array or matrix detectors, e.g. CCD camera. One other benefit is that the shape of the interferometer determines whether the spectrometer is suitable for measuring wide spectra radiation or has the ability to discriminate optical coherent radiation. Experimental results achieved for VIS and NIR range of spectra are promising. The principals of this design can be used for a variety of applications besides as a spectrometer. For example warning systems for lasers and restricted coherency sources and also filtering of optical signals and for measuring the spectral content working in a wide spectral range.
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摘要 :
In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main pri...
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In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main principle of this spectrometer is that measured collected and collimated optical radiation passes through a linear array or matrix of optical Fabry-Perot interferometers. Each interferometer is placed in front of and close to each element of the array detector. By processing the signal the spectrum of the optical radiation can be extracted. This design does not require intermediate optics between interferometer and array detector and allows for a reliable and extremely compact construction. Production cost can be low when a simple wedge type interferometer is integrated with existing array or matrix detectors, e.g. CCD camera. One other benefit is that the shape of the interferometer determines whether the spectrometer is suitable for measuring wide spectra radiation or has the ability to discriminate optical coherent radiation. Experimental results achieved for VIS and NIR range of spectra are promising. The principals of this design can be used for a variety of applications besides as a spectrometer. For example warning systems for lasers and restricted coherency sources and also filtering of optical signals and for measuring the spectral content working in a wide spectral range.
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摘要 :
In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main pri...
展开
In this work are shown the principle, first experimental results and a model design of a new type of multi channel Fourier transform (FT) spectrometer for visible (VIS) and infrared (IR) region operating in real time. The main principle of this spectrometer is that measured collected and collimated optical radiation passes through a linear array or matrix of optical Fabry-Perot interferometers. Each interferometer is placed in front of and close to each element of the array detector. By processing the signal the spectrum of the optical radiation can be extracted. This design does not require intermediate optics between interferometer and array detector and allows for a reliable and extremely compact construction. Production cost can be low when a simple wedge type interferometer is integrated with existing array or matrix detectors, e.g. CCD camera. One other benefit is that the shape of the interferometer determines whether the spectrometer is suitable for measuring wide spectra radiation or has the ability to discriminate optical coherent radiation. Experimental results achieved for VIS and NIR range of spectra are promising. The principals of this design can be used for a variety of applications besides as a spectrometer. For example warning systems for lasers and restricted coherency sources and also filtering of optical signals and for measuring the spectral content working in a wide spectral range.
收起
摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
展开
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber. In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
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摘要 :
Sensing pH in blood with an silica multimode optical fiber. This sensor is based on evanescent wave absorption and measures the change of the refractive index and absorption in a cladding made of a biocompatible Polymer. In contra...
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Sensing pH in blood with an silica multimode optical fiber. This sensor is based on evanescent wave absorption and measures the change of the refractive index and absorption in a cladding made of a biocompatible Polymer. In contrast to many existing fiber optical sensors which are based upon different dyes or florescent material to sense the pH, here presents a solution where a part of the cladding is replaced with a Poly (β-amino ester) made of 1.4-Butanediol diacrylate, Piperazine, and Trimethylolpropane Triacrylate. Piperazine has the feature of changing its volume by swelling or shrinking in response to the pH level. This paper utilizes this dimension effect and measure the refractive index and the absorption of the cladding in respect to different pH-levels. The alteration of refractive index also causes a change in the absorption and therefore the output power changes as a function of the pH level. The sensor is sensitive to pH in a wide spectral range and light absorbency can be observed for wavelengths ranging from UV to far IR.
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