Design of an optical sensor array for hydrocarbon monitoring

Abstract

Evanescent field optical sensors are accurately designed for hydrocarbon monitoring in water. Various kinds of waveguide sensors are optimized by considering a polydimethylsiloxane polymeric overlay as sensor region. The simulation results suggest that the selection of a suitable waveguide cross section can enhance the sensor performance. In particular, the hollow waveguide sensor exhibits very intriguing performance, the absorbance being quite linear with respect to the contaminant concentration. For the toluene pollution the absorbance exhibits a slope S A TE = 2.52 × 10 −2 ppm −1 for a waveguide reference length L = 1.18 mm. In order to simultaneously detect different pollutants in water such as toluene, benzene, chlorobenzene and ethilbenzene, an array of four miniaturized hollow waveguide sensors is designed.

Design of exposed-core fiber for methadone monitoring in biological fluids

“…In fact, compared with the toluene properties: i) the wavelength maximizing the benzene molar absorption coefficient are very close, ii) the lower partition coefficient of benzene is compensated for the higher absorption coefficients. Therefore, selective detection of multiple hydrocarbon water pollution could be performed via more complicated sensor arrangements, as an example via a fiber array with different PDMS methyl/phenyl group ratios [30]. Fig.…”

“…The optical fiber prototype simply proves that the sensor could be fabricated and the simulation results are intriguing for an actual application. The next steps are: i) to optimize the fiber coating process with the PDMS in order to reduce the intrinsic propagation losses, ii) to enhance the mechanical properties of the sensor, iii) to identify the best PDMS methyl/phenyl group ratios [30] to refine the sensor optimization, and iv) test/measurement of PDMS response time and reversibility to extract hydrocarbons from water solution [19,31].…”

Advances on Optical Fiber Sensors

“…In this case, the detection is obtained via transmittance or absorption measurements at the wavelength where the contaminant exhibits the highest absorption peak. In [101][102][103][104][105][106][107] optical sensing of hydrocarbons in air or in water, using UV or NIR evanescent field optical sensors was reported. Figure 15 illustrates the example of the set-up reported in [106].…”

Monitoring of Moisture in Transformer Oil Using Optical Fiber as Sensor

“…Fiber optic sensors offer unique advantages, such as immunity to electromagnetic interferences, stability, repeatability, durability against harsh environment, and fast response. Therefore, they are used for the measurement of physical parameters such as temperature [1], pressure [2], acceleration [3], curvature measurement [4], hydrocarbon monitoring [5], and host of other applications.…”