Precision Data Acquisition Research Articles

A digital long pulse integrator for EAST Tokamak

A digital integrator has been developed to be compatible with the long pulse plasma discharges on the Experimental Advanced Superconductor Tokamak (EAST), in which the induced signal is modulated by a chopper, and a field programmable gate array (FPGA) in the 16-bit digitizer is used to realize the digital integration in real time. After rectification and integration, the drift is almost linear and stable in controlled temperature, so a period of 50s is used to determine the linear drift rate for drift compensation. The integration data can be directly transferred to the reflective memory (RFM) card, which is installed in the same PCI eXtensions for Instrumentation (PXI) chassis, so the data transmission can be also done in real time. The test results show that the real time data transmission rate is up to 10kHz, the integration drift is typically less than 0.4uVs/s and drift performance is a little worse in real long pulse discharge, which can be reduced further by using more precise data acquisition.

A Low Power, Precision SAR Analog to Digital Converter for High Temperature Applications

A growing number of industries are calling for low power electronics that operate reliably at temperatures of 175°C and higher. Many of these applications require a precision data acquisition signal chain in order to digitize analog data so that it can be collected and processed. Designing circuits that meet these needs can be very challenging, requiring a data converter that can deliver high performance and reliability in these harsh environments. There are currently a very limited number of integrated circuits commercially available that are specified for operation at these temperatures, and no low power precision data converters with sample rates greater than 100kSPS. This paper presents a new 210°C rated precision analog to digital converter capable of sample rates up to 600 kSPS with 16 bit resolution while maintaining low power consumption and packaged in a small form factor. We will explore the converter architecture of this ADC, present initial test results, and show how high reliability is achieved through qualification and advanced packaging techniques.

The Development of RFID Data Management System Based on Embedded System

Embedded system in general is formed by the embedded computer system and implementing device. Embedded system is a control program stored in ROM embedded processor control board. The basic function of Radio Frequency Identification (RFID) is to realize the precise data acquisition. RFID reader via the antenna and the RFID tag for wireless communication can be achieved on the label identification code and a memory data read or write operation. The paper presents the development of RFID data management system based on embedded system. Experimental results show that the proposed algorithm has high efficiency.

Design and Implementation of the Greenhouse Environmental Monitoring System Based on JN5148

This paper designs a greenhouse environment system based on JN5148. The system uses JN5148 as the main module, setting up the wireless network with JenNet protocol stack. This system realizes true-time monitoring of environment factors which include air temperature and humidity, light intensity and CO2 concentration etc, rolling machines and pumps remote control. Test results show that system network operates stably, data acquisition precision is high, notes consume low and feedback control is accurate, and meets the application requirements of the greenhouse environment parameters monitoring.

Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y e ) of the corematerial. It is suggested that the temporal variation of Y e within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly 54–56Fe, are considered to be key players in controlling Y e ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y e ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on 54–56Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

Real-time demonstration of the main characteristics of chaos in the motion of a real double pendulum

Several studies came to the conclusion that chaotic phenomena are worth including in high school and undergraduate education. The double pendulum is one of the simplest systems that is chaotic; therefore, numerical simulations and theoretical studies of it have been given large publicity, and thanks to its spectacular motion, it has become one of the most famous demonstration tools of chaos, either through simulations or in real experiments. Although several attempts have been made to use the experiment in laboratory exercises, as the friction in the real experiment changes the nature of the motion and the values of characteristic parameters during the motion, examining the measured (dissipative) motion and comparing it with theoretical results raises several questions. In our review, we present a measurement system which is able to analyse these questions. The system, which consists of simple yet precise data acquisition electronics, easily attainable sensors, a Bluetooth module (to communicate with the PC) and open-source software, demonstrates on-line the main characteristics of chaos and the methods of its study and allows us to analyse the dissipative motion. Further information (including downloadable software) is provided on a dedicated page, http://www.inf.u-szeged.hu/noise/Research/DoublePendulum/.

Serendipity 요소법에 의한 전기비저항 3차원 모델링

전기비저항 탐사는 자동측정과 정밀한 자료 획득이 가능해 지면서 토목 및 환경문제 등 다양한 분야에 적용되고 있다. 이에 따라 시간에 따른 지하의 변화를 정밀하게 파악할 수 있는 전기비저항 모니터링 기법이 도입되면서 시간경과 모니터링 자료의 보다 정확한 모델링 기법과 역산 기법의 개발이 요구된다. 여기서는 3차원 전기비저항 모델링으로 요소의 변형을 통해 임의 형상의 이상체 및 복잡한 지형의 굴곡을 표현하기 쉬운 유한요소법을 사용하였다. 유한요소법에서 선형요소(1차 요소)는 시스템 방정식의 구성이 간단하고 대역폭이 좁다는 장점이 있다. 하지만 선형요소는 요소 또는 절점의 수에 따라 해의 수렴속도가 느리며 또한 정확성에 한계가 있다. 일반적으로 유한요소법에서 해의 정확성을 높이기 위해 고차요소를 사용한다. 본 논문에서는 고차의 Serendipity 요소를 사용하는 3차원 전기비저항 모델링 프로그램을 개발하였다. 선형요소법과 Serendipity 요소법의 비교를 위해 직육면체의 이상체 모델에 적용하였을 때, 선형요소법의 결과에 비해 Serendipity 요소를 사용하는 3차원 전기비저항 모델링의 결과에서 보다 정확하게 나타나는 것을 확인하였다. A resistivity method has been applied to wide range of engineering and environmental problems with the help of automatic and precise data acquisition. Thus, more accurate modeling and inversion of time-lapse monitoring data are required since resistivity monitoring has been introduced to quantitatively find out subsurface changes With respect to time. Here, we used the finite element method (FEM) for 3D resistivity modeling since the method is easy to realize complex topography and arbitrary shaped anomalous bodies. In the FEM, the linear elements, also referred to as first order elements, have certain advantages of simple formulation and narrow bandwidth of system equation. However, the linear elements show the poor accuracy and slow convergence of the solution with respect to the number of elements or nodes. To achieve the higher accuracy of finite element solution, high order elements are generally used. In this study, we developed a 3D resistivity modeling program using high order Serendipity elements. Comparing the Serendipity element solutions for a cube model with the linear element solutions, we assured that the Serendipity element solutions are more accurate than the linear element solutions in the 3D resistivity modeling.

Internet-Enabled Calibration Using Virtual Instrument Instead of Traveling Standard

Internet-enabled calibration, which is rapidly developing in recent years, combines the techniques of the Internet and metrology. So far, all the approaches realized for remote calibration of electrical instruments need to transfer high-accuracy units to the calibration site. This paper proposes a system using Virtual Instrument (VI) instead of traveling standard. The accuracy of data depends on the precision of data acquisition (DAQ) system and reliability of the Internet. Two basic architectures are given and several crucial techniques are discussed.

Design of an Automatic In-Out Oil Controlling and Management System Based on RF Technology

Regarding high precision and automatic control requirements for management and control system of oil depot, this paper applied RF technology in in-out oil management and automatic control theory in automatic control system of oil depot. Thus, a novel oil depot automatic in-out control system based on three level structure and RF technology was designed. In the system, the three level structures are composed of on-site control level, site management level and remote management level. A mode of combining control instruments with PLC controller was adopted in on-site control level and VB .Net was used as software for upper computer. The designed non-contact IC card management software for oil access and in-out oil control system will simplify the operation process of employees; approve levels of safe management and data accuracy for oil access in oil depot. Field tests show that this system has advantage of high control accuracy achieved 0.2 magnitude, high precision of data acquisition and easy operation for control management. The system provides an efficient technology approach for raising the level of automation and management in the oil industry.

A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment

We have built a high precision (24-bit) data acquisition (DAQ) system capable of simultaneously sampling eight input channels for the measurement of the electric dipole moment of the electron. The DAQ system consists of two main components: a master board for DAQ control and eight individual analog-to-digital converter (ADC) boards for signal processing. This custom DAQ system provides galvanic isolation of the ADC boards from each other and the master board using fiber optic communication to reduce the possibility of ground loop pickup and attain ultimate low levels of channel cross-talk. In this paper, we describe the implementation of the DAQ system and scrutinize its performance.

A Large-volume Rhizotron for Evaluating Root Growth Under Natural-like Soil Moisture Conditions

An experimental system that allows imposition of precise irrigation treatments with easy and quick observations of unrestricted root growth of woody plants was developed. The system mimics natural deep soil percolation and facilitates rapid assessment of large root populations. It was designed to be relatively inexpensive to build so that treatments could be efficiently replicated. Designs for this star-shaped rhizotron were developed and evaluated with the goals of: 1) optimizing volume and shape for minimal physical restriction and use with mature woody plants; 2) developing a drainage system comparable to natural deep soils; and 3) facilitating ease, accuracy, and duration of data acquisition. The final design allows efficient root observation, uses a wick-type drainage system to provide a near-uniform profile of soil moisture, and is easily manageable for precise long-term data acquisition. This rhizotron has eight independent viewing/sampling windows and holds 0.16 m3 of soil. An associated lightweight and compact camera positioning frame was developed that facilitates acquisition of digital photographs of soil profiles for time-series assessment of morphological and architectural parameters.

Measurement uncertainty evaluation of optical multi-sensor-measurements

Optical coordinate metrology facilitates the set-up of in-line applications for quality inspection in shop floor for a variety of products. Yet, for situations with high requirements it is not possible to fulfill all demands by devices based on a single measurement principle. To enable high measurement rates and as well as precise and contact-less data acquisition, a combination of subsystems with different principles and properties has to be implemented. To assure the fitness of an optical multi-sensor-measurement system combining a shadow system and a light-section system for the in-line inspection of concave extruding profiles, an experimental measurement uncertainty analysis has been performed. To this aim, a prototype is set-up and the effect of typical environmental influences like dust, object’s vibrations, the illuminations’ pitch error or extraneous light, is examined. Subsequently, the measurement system is evaluated under shop floor conditions and the results are analyzed.

The Portable Computer System of Wet Gas Two-Phase Flow Measurement Based on Labview

In order to measure the individual flow rate of gas and liquid of wet gas two-phase flow without separation on line in situ.a computer system for metering wet gas based on labview has been developed. In this system, a high-performance embedded computer as the core unit has been used. Meanwhile, it consists of an industrial hard disk with wide temperature,a high precision data acquisition module, an industrial 12 inch LCD with wide temperature range, a group of rechargeable lithium battery and so on. The software platform is based on labview, which can achieve signal acquisition, calculate the gas and liquid transient flowrates, display and store data, etc. The application in industrial field shows that computer system developed here has good man-machine interaction interface, high reliability and other advantages.

Online Monitoring of Biotransformations in High Viscous Multiphase Systems by Means of FT-IR and Chemometrics

In unstable emulsion systems, the determination of concentrations is a challenge. The use of standard methods like GC, HPLC, or titration is highly inaccurate and makes the acquisition of precise data for these systems complex. In addition, the handicap of high viscosity often comes into play. To overcome these fundamental limitations, the online FT-IR technique was identified in combination with chemometric modeling in order to improve accuracy. The reactor type used in this study is a bubble column reactor with up to four dispersed phases (solid catalyst, two liquid immiscible substrates, and a gaseous phase). The investigated reactions are solvent free enzymatic esterifications yielding myristyl myristate (10 mPa s) and high viscous polyglycerol-3-laurate (300-1500 mPa s), representative industrial products for cosmetic applications. For both reactions, chemometric models were successfully set up and reproducibly applied in the prediction of progress curves of a new set of experiments. This allows the automated determination of sensitive kinetic and thermodynamic data as well as reaction velocities in high viscous multiphase (bio)chemical systems.

Recording Art on Neolithic Stelae and Passage Tombs from Digital Photographs

Current research on the carved, pecked, and incised art of Neolithic stelae and passage tombs in Brittany and Ireland has required the creation of a new method of recording. This new technique has several advantages over traditional recording methods (tracing and rubbing): It is noninvasive and it allows very precise data acquisition, as well as providing an accurate record of the carved representations. The present paper describes the four stages of the process and presents its analytical capacities, using as an example the carved axe from the Table des Marchands passage tomb.

3D Nanometer Tracking of Motile Microtubules on Reflective Surfaces

Biomolecular motor-driven nanodevices are dynamic, soft systems exhibiting rapid energy flow and mechanical motion. To understand the spatial arrangement between nano-objects inthesedevices,afast,non-destructiveimagingtechniquewith nanometer spatial resolution in 3D is required. We employ fluorescence interference contrast microscopy (FLIC) to image the interaction between kinesin-driven microtubules (MTs) and nanoscopic surface structures. We directly image the geometry of crossing MTs with high temporal resolution and investigate how the leading tips of motile MTs explore their environment. We show directly that the length of the free MT tip, which is defined by the average distance between motors on the surface, determines the ability to overcome obstacles. Moreover, we demonstrate that FLIC microscopy in combination with fluorescently-labeled, motile MTs is a versatile tool to scan the geometry of engineered surfaces with nanometer height precision. This method, which is compatible with any kind of reflecting surface, permits dynamic and precise data acquisition in a highly parallel manner using a standard epi-fluorescence microscope. Active movement is a key ability of biological nanomachines, and finds applications in a number of hybrid bionanodevices. [1‐3] Molecular shuttles driven by motors and carrying cargo have been designed by us [4‐6] and others [7‐12] to address the need for nanoscale transport, positioning, and assembly systems. Our approach utilizes MTs—hollow, cylindrical, proteinaceous filaments that can be formed in vitro by self-assembly of tubulin heterodimers—as shuttles (Figure 1). MTs have an outer diameter of 25nm and can be as long as several micrometers. In a typical gliding motility assay, fluorescently-labeled MTs are transported at speeds of about 1 m ms � 1 by kinesin-1 motor proteins immobilized on a substrate surface. Kinesin motors—dimeric proteins capable of generating several piconewtons of mechanical force from the hydrolysis of adenosine 5 0 -triphosphate (ATP)—step towards the so-called ‘‘plus’’ end of the MTs. [13] Typically, several dozen motors contribute to the forward movement of one MT. Due to the high stiffness of MTs, the path that an undisturbed MT follows is normally rather straight (trajectory persistence length � 0.1 mm [14] ) and we expect a constant elevation above the surface. [15] As cargo, a wide range of objects [16‐18] including microspheres, [5] quantum dots, [19]

A Real-Time Compliance Mapping System Using Standard Endoscopic Surgical Forceps

In endoscopic surgery, the use of long surgical instruments through access ports diminishes tactile feedback and degrades the surgeon's ability to identify hidden tissue abnormalities. To overcome this constraint, we developed a real-time compliance mapping system that is composed of: 1) a standard surgical instrument with a high-precision sensor configuration design; 2) real-time objective interpretation of the output signals for tissue identification; and 3) a novel human-computer interaction technique using interactive voice and handle force monitoring techniques to suit operating theater working environment. The system was calibrated and used in clinical practice in four routine endoscopic human procedures. In a laboratory-based experiment to compare the tissue discriminatory power of the system with that of surgeons' hands, the system's tissue discriminatory power was three times more sensitive and 10% less specific. The data acquisition precision was tested using principal component analysis (R(2)X = 0.975, Q2 [cumulative (cum)] = 0.808 ) and partial least square discriminate analysis (R(2)X = 0.903, R(2)Y = 0.729, Q2 (cum) = 0.572).

Challenges in aeolian geomorphology: Investigating aeolian streamers

This paper reviews the challenges involved with instrumentation, data acquisition, analysis, and the application of theory when conducting field experiments in natural aeolian environments. This is presented in the context of a field investigation into the formation and behaviour of aeolian sand streamers. Also known as sand snakes, streamers are a familiar manifestation of pronounced spatial and temporal variability in wind-blown sand over beaches, dunes, and other sedimentary surfaces. Streamers represent complex and dynamic transport patterns that change over temporal scales on the order of 0.1 s and over a range of spatial scales from 0.1 to 10 m. These transport features are likely governed by near-surface turbulent structures in the wind, necessitating detailed measurements of turbulence dynamics in association with sediment transport patterns. This paper reviews all stages of the investigation, from field site selection to the evaluation of theoretical models. The discussion covers a range of topics, including: research strategy, site selection, instrumentation requirements and limitations, experimental design and measurement techniques, scale and precision of data acquisition, data processing and visualization, description and parameterisation of results, challenges of spatio-temporal data analysis, turbulence measurements in the saltation layer, scaling issues and non-dimensionalisations in fluid dynamics theory, and the application of theory and conceptual models to the complexities of real natural environments. The challenges discussed here apply to many geomorphological field investigations in general, and three principal issues are identified: 1) the need for inexpensive, compact, and robust instruments with high spatio-temporal resolution, 2) the lack of extended quantitative methods for the computational analysis of shapes, forms and patterns, and 3) the conceptual discrepancies and ambiguities of applying scaling parameters from experimental engineering and idealized theoretical models to complex natural geomorphic systems.

A highly sensitive MC-ICPMS method for Cd/Ca analyses of foraminiferal tests

A new, highly sensitive technique for the precise and accurate determination of Cd/Ca ratios in foraminiferal shells is presented and validated. The excellent accuracy and precision of the method reflects the application of an isotope dilution (ID) protocol for both Cd and Ca, and isotopic analysis by multiple collector inductively coupled plasma mass spectrometry. The determination of the Cd abundances involves simultaneous measurements of 110Cd and 111Cd with a dual ion counting system, whereas the ID analyses for the major element Ca were carried out by multiple collection with Faraday cups. The performance of the method was verified by analyzing multiple samples of the planktonic foraminifer Orbulina universa that were handpicked from a sediment core taken in the North Atlantic. Analyses of unspiked samples that consumed as little as ∼200 ng Ca, indicate that the Ca ID measurements are accurate to about ±0.2% (all errors are 1 RSD). For the Cd ID analyses, the accuracy and precision is about ±1.3% and ±3% for measurements that consumed 3–12 pg and 0.5–1.5 pg of Cd, respectively. Repeated analyses of spiked O. universa tests yielded a reproducibility of ±0.7% for the Cd/Ca ratio, based on measurements that each consumed about 5 pg and 700 ng of natural Cd and Ca, respectively. The method is characterized by a total procedural Cd blank of 112 ± 44 fg (1 s.d.), which results in a detection limit of 131 fg (3 s.d.). This demonstrates that the new technique is superior to published methods for the determination of foraminiferal Cd/Ca ratios, particularly with regard to the acquisition of precise data for samples of limited size.

Precise determination of cadmium isotope fractionation in seawater by double spike MC-ICPMS

A new technique has been developed for the accurate and precise determination of the stable Cd isotope composition of seawater. The method utilizes a 110Cd– 111Cd double spike, and it involves separation of Cd from seawater by column chromatography and isotopic analyses by multiple collector inductively coupled plasma mass spectrometry. As a by-product, it also generates precise Cd concentration data. Repeated analyses of three pure Cd reference materials and three seawater samples yielded reproducibilities of about ±1.0 to ±1.6 ε 114/110Cd (2 SD), based on measurements that each consumed about ∼8 ng of natural Cd ( ε 114/110Cd is the deviation of the 114Cd/ 110Cd isotope ratio of a sample from the standard in parts per 10,000). This demonstrates that the new double spike technique is superior to published methods of Cd isotope analyses, with regard to the acquisition of precise data for samples of limited size. Additional experiments showed that as little as 1–5 ng of seawater Cd could be analyzed with a precision of about ±2 to ±6 ε 114/110Cd (2 SD). The accuracy of the seawater isotope data was ascertained by experiments in which a Cd-free seawater matrix was doped with small quantities of isotopically well-characterized Cd. Repeated mass scans that were carried out on purified Cd fractions of several samples furthermore demonstrated the absence of significant spectral interferences. The isotope data that were acquired for the three seawater samples reveal, for the first time, small but resolvable Cd isotope fractionations in the marine environment. Cadmium-rich intermediate water from the North Pacific was found to have an isotope composition of ε 114/110Cd = 3.2 ± 1.0. In contrast, Cd-depleted seawater from the upper water column of the Atlantic and Arctic Oceans displayed isotope compositions of ε 114/110Cd = 6.4 ± 1.1 and 6.6 ± 1.6, respectively. These observations are in accord with the interpretation that the isotope effects are due to the biological fractionation that occurs during the uptake of dissolved seawater Cd by phytoplankton.