Array Measurement System Research Articles

Experimental study of oil-water two-phase flow patterns in a vertical large diameter pipe

The flow structure and the phase inversion have great influence on the flow measurement in vertical upward oil-water two-phase flow. This paper attempts to investigate the flow patterns in oil-water flows through a vertical upward large pipe with the designed mini-conductance array probes measurement system and the vertical multi-electrode array (VMEA) measurement system. According to the output waveform of the mini-conductance array probes, the oil-in-water flow, transition flow and water-in-oil flow can be identified effectively. The fluctuating signals of the VMEA is processed by the recurrence plot and the time-frequency representation, the results show that the VMEA conductance signal with average measurement characteristics can realize an effective identification of the above three flow patterns, which has a good agreement with the results of the mini-conductance array probes. Finally, via comparing with previous published flow pattern transition boundary models in different pipe diameters, it is founded that the boundary line of the transition to oil-in-water based on the kinematic wave-based model and the observation-based model in the same diameter pipe are consistent with our experimental data. And the pipe diameter affects the flow pattern transition, compared with the boundary in small diameter pipe, the phase inversion requires a larger oil velocity, and the transition zone becomes narrower in large diameter pipe.

Measurement and Evaluation of Metal-to-Metal Seals Sealability by Ultrasonic Phased Array

The magnitude and distribution of contact stress on the metal-to-metal seal interface of premium connection has been confirmed as a direct factor of the sealing integrity. In this study, the method of evaluating sealability by measuring contact stress on metal-to-metal seals with the ultrasonic phased array is investigated. A loading system and ultrasonic phased array measurement system of cone-cone contact samples were created. The recommended detection method is focusing -deflection, and the time compensation method is suggested to extract the reflected wave peak of the sealing surface. The experiments show that the reflected wave peak declines with the rise of the axial load, with the big end showing the most noticeable reduction. The shift in the reflected wave peak also reflects the axial movement of the contact interface. The contact stress is calculated according to the reflection coefficient and compared with the simulation results. The distribution trend of contact stress is consistent. The sealing index measurement error is less than 15%, and the measurement error is decreased with the decrease of the sealing surface angle. Then, the nephogram of contact stress distribution on the sealing surface is formed to visualize the contact stress, which takes on great significance in engineering.

Multichannel gas electron multiplier based soft x-ray field-programmable gate array measurement system for W-Environment in Steady-state Tokamak (WEST): Hardware, installation, and first plasma acquisition.

The work describes a novel approach to the design of a fast, multichannel measurement system for plasma diagnostics [A. Wojenski et al., Fusion Eng. Des. 123, 727 (2016)]. Its main scope is to provide measurements of soft X-ray (SXR) emission during plasma phenomena at the W-Environment in Steady-state Tokamak (WEST), especially for monitoring and tracing tungsten impurities. This paper describes the vertical Gas Electron Multiplier (GEM) camera installed at the WEST [M. Chernyshova et al., J. Instrument. 10, P10022 (2015)]. The designed GEM detector readout board has more than 100 channels, resulting in high-performance requirements for the data acquisition and processing system. The novel system construction approach is that the unit works on the raw signals providing a high quality of the data, especially in the scope of pileup effect analysis. In the case of doubtful results, the source data can be easily reviewed offline. The data selection and transmission are done in Field-Programmable Gate Arrays (FPGAs) on the custom boards with the custom Peripheral Component Interconnect (PCI)-Express Gen2 switch that allows us to register signals from multiple FPGAs and then process the data by complex algorithms [G. Kasprowicz et al., J. Fusion Energy 38, 480 (2019)]. The firmware is replaceable and different working modes can be applied (some under verification): global trigger mode, high-speed data serialization, and extended signal registration. Low level optimized central processing unit software for data readout was also designed [P. Linczuk et al., J. Instrum. 14, C05001 (2019)]. The installation of the system is described due to complex system components' distribution. The first results of the successful acquisition of the plasma at the WEST are discussed. The corresponding SXR energy and topology spectra were computed. Those are the first technical measurements of the system to ensure verification of data quality.

Phase Shift and Amplitude Array Measurement System Based on 360° Switched Dual Multiplier Phase Detector

This article presents an amplitude and 360° phase shift array measurement system. The basic cell of the measurement system uses a novel amplitude and phase detector based on switched dual multipliers. The phase shift measurement is characterized using an analog phase detector (mixer), detecting a maximum range of ±90°, and a double multiplication of the input signals, in phase and phase shifted. This method broadens the frequency and amplitude range beyond other solutions that require fulfilling the quadrature condition. This method broadens the frequency and amplitude beyond other solutions requiring fulfilling the quadrature condition or phase and amplitude balance. Thus, it enables to compensate significant phase imbalance in the 90° hybrid or use amplitudes out of the range that ensures the switching operation of mixer diodes. The circuit calibration that allows compensation for errors (amplitude, phase shift, mismatching, etc.) is detailed, and its relation to the required measurement accuracy is discussed. The design can be easily extrapolated to other frequency ranges because it uses commercial RF devices available in a wide frequency range and avoids the need of crossing lines or complex 90° hybrid. A prototype with $3 \times 3$ cells has been built to evaluate various test conditions on $1 \times 3$ cell configurations that show the advantages of the procedure. It should be highlighted that the cell prototype uses devices that will be operating outside the frequency and amplitude ranges recommended by their manufacturers. A calibration from 2.6 to 6 GHz and −15 to −3 dBm was performed to evaluate the measurement errors. An analysis of the isolation between cells and different calibration configurations is performed to analyze the measurement errors. Measurements show compensation of +30°/−25° phase imbalance and 13-dB power lower than mixer manufacturer recommendation.

Inversion method of the key structure parameters of light screen array measurement system using genetic algorithm

To effectively improve the measurement accuracy of the light screen array measurement system (LSA for short) in the evaluation of continuous rapid-firing weapon, the paper presents an inversion method to obtain the key structure parameters of LSA based on genetic algorithm. First, we systematically introduce a measurement model based on the key structure parameters of the LSA. Second, we establish an objective function through the validation of the measurement results. Next, an inversion method is derived to generate many groups of structural parameters within the allowable error range. Finally, we can adopt a genetic algorithm to obtain a group of the key structural parameters which are the closest to their truth value. Through simulations and experiments, results show that the measurement model is corrected because of the key structural parameters through the inversion, and thus the accuracy of the LSA is effectively improved.

Adaptive filtering-based current reconstruction in non-contact magnetic sensor array measurement system

Adaptive filtering-based current reconstruction in non-contact magnetic sensor array measurement system

Improvement of the detection sensitivity uniformity of an indoor light screen array measurement system with large field of view angle using multi-lens splicing

The research addresses an effective method based on multi-lens splicing to improve the detection sensitivity uniformity of an indoor light screen array measurement system (LSA for short) with large field of view angle. According to the principle of its lens photometry, we derive the mathematical model of detection sensitivity of the LSA scientifically. Furthermore, we can employ several lenses to splice a large field of view angle to ameliorate the uniformity of the sensitivity distribution of the indoor LSA. Finally, we discuss some key factors of the improved LSA and optimize them successfully. Through simulation and experiment, the results show that the uniformity of detection sensitivity of the indoor LSA using three-lens splicing increases by 47.4% relative to conventional one-lens LSA. Thus, the proposed method can enhance the detection performance of indoor LSA effectively.

Evaluation method for the performance of light screen array measurement system based on semi-physical simulation

The paper presents a method to evaluate the performance of light screen array measurement system (LSA for short) objectively and scientifically. We put forward the scheme of semi-physical verification platform based on arbitrary waveform generator (AWG), and this instrument is used as a substitute for light screen detector in the LSA. according to some main characteristics of dynamic signal, the waveform files of two simulation signals with a certain time interval are compiled and created through configuring some options through a signal waveform edition software. Furthermore, these waveform files are downloaded into the AWG to generate two channel simulation signals. Then, the time interval of these two signals can be measured in the signal acquisition & processing module of LSA. Finally, we can compare the difference between true values and measured results. Through experiment and analysis, the proposed method can meet the requirement of performance evaluation on the LSA, and it is superior to the other previous methods.

Measurement model and algorithm for measuring flight parameter of parabolic trajectory by six-light-screen array

To solve errors of current light-screen array in terminal trajectory measurement, a measurement model and algorithm for calculating the external trajectory flying parameters of the projectile with variable velocity and parabolic trajectory basing on the six-light-screen array are put forwarded in the paper. The spatial position of the light-screen array is analyzed, planar equations are constructed by analytic geometry. This study also investigates the impact of gravity and air drag force on projectile flight trajectory and establishes a space trajectory equation of projectile. The spatial impacting position, the velocity and the velocity reversal angles of a projectile can be correctly calculated with target placement parameter and time sequence of the projectile passing through the light-screen array. Measurement formula and calculation method are deduced in consideration of the influence of gravity only and the influence of gravity and air drag force. To verify the validity of the research method, this study adopts XGK-08 type six-screen array measurement system and wooden target to compare the projectile impacting coordinates of 7.62mm rifle cartridge. Result shows that when the detecting area is 3×3m2, the coordinate measurement error of the model is less than 2.5mm.

High resolution acoustic measurement system and beam pattern reconstruction method for bat echolocation emissions

Measurements of the transmit beam patterns emitted by echolocating bats have previously been limited to cross-sectional planes or averaged over multiple signals using sparse microphone arrays. To date, no high-resolution measurements of individual bat transmit beams have been reported in the literature. Recent studies indicate that bats may change the time-frequency structure of their calls depending on the task, and suggest that their beam patterns are more dynamic than previously thought. To investigate beam pattern dynamics in a variety of bat species, a high-density reconfigurable microphone array was designed and constructed using low-cost ultrasonic microphones and custom electronic circuitry. The planar array is 1.83 m wide by 1.42 m tall with microphones positioned on a 2.54 cm square grid. The system can capture up to 228 channels simultaneously at a 500 kHz sampling rate. Beam patterns are reconstructed in azimuth, elevation, and frequency for visualization and further analysis. Validation of the array measurement system and post-processing functions is shown by reconstructing the beam pattern of a transducer with a fixed circular aperture and comparing the result with a theoretical model. To demonstrate the system in use, transmit beam patterns of the big brown bat, Eptesicus fuscus, are shown.

Resolution of amino acid mixtures by an array of potentiometric sensors based on boronic acid derivative in a SIA flow system

The objective of this work was to perform the quantitative analysis of 4 amino acids mixtures: phenylalanine, tyrosine, ornithine and glutamic acid. For this purpose a potentiometric sensor array (electronic tongue) and Sequential Injection Analysis (SIA) measurement system were employed. The flow-through sensor array was composed of 6 miniaturized classical ion-selective electrodes based on polymeric membranes (plasticized PVC) containing 4-octyloxyphenylboronic acid as an ionophore and/or an ion exchanger. Partial Least Squares (PLS) analysis of the steady-state sensor array responses, measured in amino acids mixtures prepared by the SIA system (in two buffer solutions), permitted a correct quantitative analysis only of glutamic acid and ornithine. While a further chemometric treatment, involving the extraction of dynamic components of the transient response employing the Wavelet transform, the removal of less-significant coefficients by means of Causal Index pruning and training of an Artificial Neural Network (ANN) with the selected coefficients, allowed the simultaneous determination of the four amino acids.

Novel ultrasound array measurement system for flow mapping of complex liquid metal flows

In magnetohydrodynamics, model experiments are commonly conducted to investigate the interaction between magnetic fields and electrically conductive fluids. The available flow instrumentation for opaque fluids usually lacks the ability to capture and visualize a velocity field in one shot. We present a multidimensional ultrasound array Doppler velocimeter that employs multiple line arrays of transducers and allows the resolution of small scale structures in complex flows. The system achieves a lateral resolution up to 3 mm, an axial resolution of approx. 1.4 mm and frame rates up to 30 Hz in metal melts at room temperature. A flexible sensor arrangement allows for various measurement configurations, e.g. four planes can be measured simultaneously with one velocity component, two planes with two components or two lines with three components. We present an experiment in a square-shaped container driven by a rotating magnetic field and results of a model experiment for continuous steel casting. The measurement system has proven to be a powerful tool for research in magnetohydrodynamics.

A new method of machinery diagnosis monitoring based on the acoustic imaging measurement

Abstract A new method has been developed to perform a fantastic diagnosis monitoring for different kinds of machines, including small as computer, shaver, hand phone, or large as 4000hp engine, slow as a walking, or fast as flying in sky, based on acoustic imaging technology with a microphone array measurement system. With it noise field of machine can be analyzed from its sound image coupled in video in door and out door, even in some extent reverberated space. It is particularly useful to analysis large machine with multi noise source and low noise level machine. Comparing to traditional vibration measurement, this method can locate the diagnosis' center and separate every source with 15dB sub-lobe suppression.

The Application of an Array of Sensors based on Boronic Acid Derivative for the Quantitative Analysis of Amino Acids

Abstract The objective of this work was to perform the quantitative analysis of 4 amino acids: phenylalanine (Phe), tyrosine (Tyr), ornithine (Ort) and glutamic acid (Glu) in mixtures with the use of potentiometric sensor array (electronic tongue) and Sequential Injection Analysis (SIA) measurement system. The flow-through sensor array was composed of 6 miniaturized classical ion-selective electrodes based on polymeric membranes (plasticized PVC) containing phenylboronic acid ionophore and/or an ion exchanger. The PLS analysis of the sensor array responses, measured in amino acids mixtures prepared by the SIA system (in two buffer solutions), permitted a correct quantitative analysis of only Glu and Ort. Further chemometric treatment, involving the extraction of dynamic components of the transient response employing the Fourier transform plus training of an Artificial Neural Network (ANN) with its coefficients led to the simultaneous determination of 3 amino acids, with a separate semiquantitative estimation of Tyr.

Multichannel Biosensing and Stimulation LSI Chip Using 0.18 µm Complementary Metal–Oxide–Semiconductor Technology

We designed 8-channel preamplifiers and multisite stimulation circuits on a 2.5 ×1.4 mm2 chip using a 0.18 µm complementary metal–oxide–semiconductor (CMOS) process for a microelectrode array measurement system. The size of a 1-channel preamplifier including a DC store/adder circuit is 930 ×120 µm2. An 8-channel programmable stimulator was integrated on the same die. The preamplifier circuits can amplify a small neural signal with a low noise and a low power consumption (2 mW/ch) using a chopper operation. The stimulation circuits can apply a voltage of ±700 mV to any channel and with any timing using serial digital data control. The performance of the biphasic stimulation waveform generated by the designed LSI chip is the same as that generated with a conventional stimulation system. These functions were confirmed by connecting the LSI chip to a conventional measurement system. The system miniaturization achieved using the custom LSI chip will offer great advantages in terms of future brain machine interface applications.

Community Effect on Drug Sensitivity of Cardiomyocytes Controlled Spatial Patterns by using On-Chip MEA System

In cardiomyocyte network, network size and spatial arrangement of different cellular-type are important factors for stabilization of beating rhythms. To study the community effect of the geometric factor and community size, we tried to develop cultivation chambers in a various size and geometric patterns using the agarose micro-processing technique combined with the multi-electrode array (MEA) measurement system (we call it On-Chip MEA system), and each of extra-cellular signal of mouse embryonic cardiomyocytes to tachyrhythmia inducing drug response was recorded simultaneously.Firstly, to evaluate the effect of community size on the sensitivity to drug, we tried to build the square sheet type chambers having small, medium and large area (about 104, 105, and 106 um2, respectively). Next, we tried to construct circuit type chambers with loop structure (circuit length of 2um, 8.2um) compared with sheet type geometry.As a result, we observed different response to drug among community size and geometric pattern. These results imply that sensitivity to the drug depends on spatial patterns. In this meeting, difference of drug sensitive event (e.g. tachyrhthmia, cardiac arrest etc), we report in detail about quantitative parameters: Beating Rate (BR), Field Potential Duration (FPD), Short Term Variability (STV) of them etc, which will be help for understanding community effect.

Community Effect to the External Electrical Stimulation on Cardiomyocytes by using On-Chip MEA System

In the cardiomyocyte network, network size and spatial arrangement of different cellular-type are important factors for reducing the fluctuation of the beating rhythms. To study the community effect on the cell network, experimental conditions need to control the community size and to construct the network in a stepwise manner. Therefore, we tried to develop a various size of cultivation chamber using the agarose micro-chamber system combined with the multi-electrode array (MEA) measurement system (we call it On-Chip MEA system).

Calibration of a novel four‐dimensional diode array

The aim of this work is to develop effective calibration methods for a novel fourdimensional (4D) diode array for pretreatment verification of intensity-modulated radiation therapy (IMRT) and rotational therapy. A novel 4D diode array (ArcCHECK, Sun Nuclear, Melbourne, FL) was developed to meet the needs of appropriate and efficient quality assurance for IMRT and especially rotational radiotherapy. The diode array presents a consistent detector image in beam's eye view at arbitrary gantry angles due to isotropic arrangement of diodes in a three-dimensional (3D) cylindrical phantom. The 50 ms simultaneous update of all diodes on the detector array (fourth dimension) makes it capable of time-resolved beam delivery analysis with any rotational delivery techniques. The calibration procedure consisted of delivering and measuring a series of calibration beams with 5.8 degrees angular spacing surrounding the cylindrical diode array. Correction factors for diode intrinsic sensitivity and directional response dependence were derived from these measurements. A real-time algorithm to derive gantry angles based on the detector signal was developed to interpolate and apply the corresponding angular correction factors. The calibration was validated with ion chamber scanned beam profiles in a 3D water tank. Excellent agreement was observed between diode array measurement and treatment planning system calculation. The accuracy of the gantry angle derivation algorithm was within 1 degree which caused a less than 0.2% dosimetric uncertainty. With the proposed calibration method and the automatic gantry angle derivation algorithm, the 4D diode array achieved isotropic detector response and is suitable for both IMRT and rotational therapy pretreatment verification.

Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm.

Measurements of sound propagation in a littoral environment using a vertical synthetic array

Shallow-water propagation experiments were carried out in St. Andrews Bay, Florida. These investigations used a vertical one-dimensional synthetic array measurement system where two hydrophones incrementally mapped the acoustic pressure from 2m below through 2m above the sand-water interface. A broadband (1 to 12kHz) chirp was used to insonify the water channel. The source to receiver distance was varied and included measurements at 20, 30, 50, 70, and 90m. These measurements quantified the acoustic pressure above and below a sandy bottom and the results are presented along with frequency analysis, temporal impulse analysis, and wave number analysis. To obtain a better understanding of the results, the measurements are compared to two numerical models. The first model is a temporal ray path prediction of sound propagation in the water channel. The second model, range-dependent acoustic model (RAM), based on a parabolic equation, predicts the sound propagating in a water channel with a sandy bottom. The experimental results agreed well with both numerical predictions in the water column. However, the measured acoustic energy in the sandy bottom was different from the prediction by RAM, which assumed a smooth air-water and water-bottom interface and a point source.