Flatness of surface is of great importance in industrial products such as steel sheets. In many cases, the quality of the final product is directly linked to the flatness of its components. One possible defect in the production of hot strip mill steel sheets is the straightness defect which results in flatness asymmetries in the steel sheets, causing a certain curvature on its edges. This defect is more likely to occur at the final stages of the hot strip mill. The deformation may cause stoppages in the rolling process and damage to the machinery. Detection and measurement of these asymmetries can be fed back to the previous stages of the rolling process for proper adjustment of the roller's speed to avoid further defects. Nowadays, a family of methods for surface detection, called topometry, is available for measurement of surface flatness asymmetries. In this paper, a method is proposed based on Interferometric Fringe Projection (IFP) which performs the flatness measurement. The proposed method has the advantage of simplicity and can, hence, be used in real-time applications.

Flow measurement underwater oil leak is a challenging problem, due to the complex nature of flow dynamics. Oil jet flow associated with a multi-scale coherent structure in both space and time direction. Optical plume velocimetry (OPV) was developed by (Crone, McDuff, and Wilcock, 2008), and it was the most accurate technique that used for oil leak flow measurement. Despite its better estimation, the OPV measured the oil flow rate with high uncertainty of 21%. This is due to the multi-scale phenomena of oil flow, as well as the limited accuracy of direct cross correlation (DCC) typically used by OPV. This paper proposed a novel technique that considers the multi-scale property of turbulence in flow measurement. The proposed technique is based on continuous wavelet transform and estimates the flow using the following steps: Decomposition of turbulent flow signal by using continuous wavelet transform (CWT), correlation coefficient estimation in which Fast Fourier Transform (FFT) algorithm was used, interpolation and peak detection for the estimated correlation coefficients, and finally, the velocity field estimation. In order to validate the CWT-based technique, a turbulent buoyant jet, which has a similar flow-type of oil jet was experimentally simulated. Then, the CWT-based technique was applied to measure the jet flow, and the outcomes of the technique was compared to the experimental results. As a result, utilizing a smaller number of wavelet scales lead in better flow measurement as compared to the use of larger scales. CWT-based technique was accurately estimated the jet flow rate with standard error of 0. 15 m/s, and outperformed the classical algorithms, including FFT, and DCC algorithms, which were measured with error of 3. 65 m/s and 4. 53 m/s respectively.

There are fewer problems encountered with optical voltage transducers in comparison with their inductive and capacitive counterparts. Although capacitive and inductive transformers are used vastly for the purpose of measurement and protection in the networks, they cause problems such as core saturation and improper transient responses which decrease the accuracy of measurement and efficiency of the protection schemes. As a result, optical voltage transducers are considered as proper candidates for replacing the conventional inductive and capacitive transformers. Lighter weight, smaller size, larger dynamic range, wider bandwidth, insensitivity to electromagnetic interference, stability over temperature change, absence of iron core saturation, low maintenance and replacement cost, etc. are some of the advantages of optical voltage transducers over inductive and capacitive transformers. In this paper, the Modified Adaptive Method is introduced in order to measure the integral of electric field with minimum number of sensors. Using this algorithm makes the effects of other fields minimum. One more advantage of this method is the possibility of improving the accuracy of the measurement by using a correction factor. The correction factor is determined by considering the level of accuracy, environmental conditions and the number of sensors. Simulation results show the great validity and effectiveness of this method over a wide range of variations.

Micro-cantilever arrays with different dimensions are fabricated by micromachining technique onto silicon<1 0 0> substrate. These sputtered gold-coated micro-cantilevers were later surface-functionalized. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical diffraction with laser source are employed to characterize the morphology and image measurement of the micro-cantilever arrays, respectively. The spatial resolution produced in the proposed image measurement method is approaching 1mm, and the repeatable precision is confirmable in nanometers. Compared with conventional AFM and SEM measurement techniques, the proposed method has demonstrated sufficient flexibility, repeatability, and reliability. The experimental results have been analyzed and presented in this paper for MEMS micro-cantilevers. The scanning white light interferometry based, two-point high-resolution optical method is presented for characterizing micro-cantilevers and other MEMS microstructures. In this piece of work, we investigate the microstructure fabrication and image measurement of geometrical parameters such as length, width, and step height of micro-cantilevers fabricated using bulk micromachining technique onto silicon<100>substrate.

The broadband optical absorption properties of silicon nanowire films fabricated by electroless metal deposition technique followed by HF/Fe (NO3) 3 solution-based chemical etching at room temperature on p-type silicon substrates have been measured and found absorption higher than that of the solid thin films of equivalent thickness. The observed behavior is effectively explained by light scattering and light trapping though some of the observed absorption is due to a high density of surface states in the nanowires films. Synthesized structures absorbed more than 82% of incident radiation in case of Cu-deposited silicon nanowires, whereas for Ag it was maximum 83%, which is much greater than that of the bulk silicon as they absorbed maximum 43% of the radiation.

Purpose: To estimate the power of an implanted intraocular lens (IOL) by measuring IOL thickness using anterior segment optical coherence tomography (AS-OCT) and to assess the repeatability of measurements. Methods: Ninety-seven eyes were studied one month after uneventful phacoemulsification within the bag Acrysof SA60AT IOL implantation (range +11 to +35). All eyes had postoperative refraction of ±0. 5 D of target refraction. AS-OCT was used to measure the central thickness of the IOL. Correlation between labelled IOL power and central IOL thickness as well as the measure of repeatability, for example, intraclass correlation coefficient (ICC), were evaluated. IOL thicknesses were also calculated using a formula and compared with AS-OCT-derived measurements. Results: IOL thickness correlated significantly with labelled IOL power (R2 = 0. 985, P < 0. 001). The regression equation (IOL Power = [0. 04 × IOL thickness in micron] – 7. 56) indicates 25 microns of central IOL thickness change per 1D power change. Over the studied range, IOL power could be estimated with a precision of 0. 85 ± 0. 02 D (95% confidence interval: 0. 83–0. 94D). ICC for repeated measurements was 0. 999. There was a significant correlation between calculated and measured (AS-OCT) IOL thickness (R2 = 0. 984, P < 0. 001). Conclusion: Central IOL thickness measurements with the AS-OCT are highly repeatable and closely correlated with the labelled IOL power, which can predict the IOL power with ±0. 85 D from the actual power. This method can be helpful in cases of postoperative IOL surprise.

This article proposes a paper-based microfluidic chip that can non-invasively measure glucose with optical detection technique using NIR. This paper chip is disposable, portable, low-cost, lightweight, and suitable for point-of-care and cost-effective tests. This paper chip is fabricated with a kind of photoresist that is used in the publishing industry called UV curable resin. This method is chip, simple, and suitable for mass production. This paper chip is used for measuring glucose non-invasively and an interface sensor is designed with an NIR technique that can measure glucose concentration between 60 to 500 mg/dl with voltage range of 630 to 730 mV.

This paper demonstrates a method for obtaining accurate voltage from discrete field sensors; named quadrature method. In using this method, a few number of field sensors is sufficient and it is shown that it can be a tool for measuring electric field and designing voltage transducers. This method would not require a special insulation or electric shielding that is required in most conventional voltage transducer technologies of today. Simulation results show the good accuracy of the method.

This paper introduces an optical measurement system for shock wave characteristics. The system works by mounting a metal plate attached to spring mounts against the shock wavefront. This set is sealed and can plot the shock wave pressure diagram by measuring plate's displacement, radiation and changing the reflection of light during shock wave conflict, and converting these optical data to voltage. In the experiments with the optical system, there was no delay time in the wave impact response. Using the optical system and the fixture designed and built, it is also possible to measure the velocity of moving objects and monitor the planar shock wave formation in addition to the shock wave velocity. Then the calibration was performed with the help of a standard piezoresistive sensor in a cold diaphragm shock tube, with a pressure of 5. 5 to 12. 5 bar by performing 12 tests. Relations and figures for output voltage and shock pressure are also explained.