Papers by Keyword: Simultaneous Measurement

Abstract: The work describes the constructions of optical fiber based minimal invasive sensing system to measure pH and dissolved oxygen using sol-gel membranes which are attached internally in any transparent container. The disposable sensing membranes are very thin size and prepared as fluorescent dye doped in silica film using simple procedures. The sensor characteristics such as response time, linearity, repeatability and reversibility are evaluated and the performance of the sensor also compared with commercial meters. The experiments such as, chemical stability and photo stability are also carried out. The detection limit of pH sensor is found between 3 pH and 10 pH, however good sensitivity is obtained for the ranges from 4 pH and 9 pH with the response time of 7 seconds. Non-linear response is obtained for dissolved oxygen sensor and it is made linear by applying Stern-Volmer equation. The oxygen sensor shows good sensitivity in the ranges from 2 mg/L to 8 mg/L.

Abstract: The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

Abstract: The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

Abstract: Simultaneous measurement of strain and temperature was demonstrated by using a long-period fiber grating inscribed on a polarization-maintaining fiber. This paper analyses the intersect senstive questions in terms of strain and temperature of fiber optic cable material. It also proposes a new way to carry out simultaneous measurements of strain and temperature. Experimental results show mean square deviations of 15.6 με and 0.7°C for strain and temperature, respectively.

Abstract: We introduce an all-fiber sensor capable of simultaneous measurement of temperature and refractive index (RI). The sensor system consists of a single mode fiber Bragg grating (FBG) and a single-mode-multimode-single-mode (SMS) structure which serves as a Mach-Zehnder interferometer (MZI), and the multimode fiber (MMF) is etched by hydrofluoric acid solution. The experimental results demonstrate that the temperature sensitivities of FBG and MZI are 0.016nm/°C and 0.093nm/°C, respectively, and the RI sensitivity of MZI achieves 226.25nm/RIU. The interesting properties of the sensor include compact size, high sensitivity and good operation linearity.

Abstract: A system was developed for simultaneously measuring stress and temperature in structures in time series. The stress and temperature were measured using the photoelastic technique in the form of phase stepping and the thermographic technique, respectively. Four phase-stepped photoelastic images were captured simultaneously using beam-splitting optics. A beam splitter was used for transmitting light in the visible range while simultaneously reflecting light in the infrared range. The system was applied to ultraviolet curing resin with a step part illuminated with ultraviolet rays, and the stress and temperature in the curing process were measured. Results showed that the stress and temperature in the curing process can be measured simultaneously in time series using the system. The step part of the resin affected the distribution of the stress and temperature

Abstract: In this paper, we apply phase-shifting digital holographic interferometry to simultaneous measurement for out-of-plane and in-plane displacements by employing two beam illuminations for an object. Phase-shifted holograms before and after displacements of the object using each of two beams are recorded by a CCD camera, separately. The complex amplitude at each pixel of the CCD plane is analyzed from the holograms taken with phase-shifting. The complex amplitude of he object is reconstructed from the complex amplitude distribution on the CCD plane using the Fresnel diffraction integral. Each directional phase difference distribution is obtained by calculating the phases before and after deformation for each directional beam. The phase distribution for out-of-plane displacements is obtained by calculating the sum of the two phase difference distributions. The phase distribution for in-plane displacements is obtained by calculating the difference of the two phase difference distributions. The phase values provide accurate displacement distribution information. Actually, when the object deforms in both out-of-plane and in-plane directions, it is possible to analyze the displacement distribution in each direction. The theory and an experiment are shown.