Development of Metal-Ceramic Coaxial Cable Fabry-Pérot Interferometric Sensors for High Temperature Monitoring

Abstract

Metal-ceramic coaxial cable Fabry-Pérot interferometric (MCCC-FPI) sensors have been developed using a stainless steel tube and a stainless steel wire as the outer and inner conductors, respectively; a tubular α-alumina insulator; and a pair of air gaps created in the insulator along the cable to serve as weak reflectors for the transmitting microwave (MW) signal. The MCCC-FPI sensors have been demonstrated for high temperature measurements using MW signals in a frequency range of 2–8 GHz. The temperature measurement is achieved by monitoring the frequency shift (Δƒ) of the MW interferogram reflected from the pair of weak reflectors. The MW sensor exhibited excellent linear dependence of Δƒ on temperature; small measurement deviations (±2.7%); and fast response in a tested range of 200–500 °C. The MCCC has the potential for further developing multipoint FPI sensors in a single-cable to achieve in situ and continuous measurement of spatially distributed temperature in harsh environments.

A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing

“…Each channel was generated from each Fabry-Perot sensor. Other quasi-distributed fiber optic sensors can be found in references [ 31 , 32 , 33 , 34 , 35 , 36 ].…”

A metal-ceramic coaxial cable Fabry-Pérot microwave interferometer for monitoring fluid dielectric constant

“…[6][7] More recently, we developed a new type of metal-ceramic coaxial cable FPI (MCCC-FPI) sensor for measurement of high temperature (up to 1000 o C). [9] The MCCC-FPI consisted of metal tube and wire as outer and inner conductors, respectively, and ceramic tubes as insulators where a pair of small-width air gaps was created to serve as reflectors. In these reported CC-FPI sensors, the interreflector insulation segments were of the same materials as those in their respective original cables for convenience, and hence  r =  r,1 .…”

“…The experimental data ( . ) are also compared with the predictions given by the Maxwell-Garnett (M-G) relation for spherical solutions, the Burggeman extended M-G for highly dispersed liquid mixtures, and the Bottcher model of effective medium, which are expressed by equations (7)(8)(9). [20][21][22] Maxwell-Garnett:…”

Characterizing the Gas adsorption-dependent Dielectric Constant for Silicalite Nanoparticles at Microwave Frequencies by a Coaxial Cable Fabry-Pérot Interferometric Sensing Method

“…The understanding of zeolites' dielectric behaviors and their relationship with molecular adsorption in the zeolitic pores of nanometer or sub-nanometer scales has been hindered by the lack of simple and reliable measurement technologies. Currently, the widely used capacitance measurement approach applies to low frequency ranges while the conventional techniques for measurements in microwave frequency ranges often involve challenging and costly device fabrication and encounter difficulties in controlling sample conditions during operation [9,10]. This paper reports the measurement of dielectric constant for pure silica MFI-type zeolite (i.e.…”