Computer-controlled Measurement System Research Articles

Shaping and Geometrical Analysis of the Ring-type Test Samples Used in Dimensional Measurements by a Bench-Type Multisensor CMM

The routine measurements of various geometrical quantities in industrial applications are realized by use of a range of optical methods. Optical metrology is a dynamically developing area of the modern science and technology using a hardware solution from simple sensors to advanced computer-controlled measurement systems. In many specific applications dedicated measurement systems are required, which are characterized by much better metrological parameters and wider measuring capabilities than typical systems. Testing of such systems must be carried out on objects with similar properties as the actual objects produced in industrial conditions. The hybrid system for non-contact simultaneous assessment of the surface texture and dimension developed in Koszalin University of Technology (Koszalin, Poland) specially produced sets of ring-type samples with a variable external diameter φz=20.5-30±0.2 mm. This paper presents theprogress of works related to the design, production and analysis of the geometrical dimensions of such sets of test samples prepared for dimensional assessment by using laser triangulation methods. All the stages of this work are all so described and detailed in this paper. These stages included: the determination of assumptions for the preparation of samples, the choosing and characterising of the materials used for samples, the machiningwith a specialized bench-type lathe SK-1, as well as the dimensional measurements used by simple hand measuring instruments and the advanced bench-type coordinate measuring machine Video-Check®-IP 250 produced by Werth Messtechnik GmbH. The results obtained, which were presented in the form of bar diagrams and detailing already discussed, confirmed the dimensional correctness of the machining that was carried out.

Improvement of QDaedalus measurements with continuous detection of environmental parameters

QDaedalus is an automated, computer-controlled astro-geodetic measurement system. Astronomical deflections of the vertical measured by the QDaedalus system are significantly influenced by atmospheric refraction. Therefore, the measuring system was further improved by recording the environmental parameters influencing the refraction (air pressure, temperature, humidity) with accurate and high time resolution. In addition to meteorological parameters, refraction also depends on the spectrum of the stars. Both the continuously measured meteorological parameters and the color of the stars were taken into account in the calculation of the refraction. To control the method, we used the deflection of the vertical values of the Pistahegy point in the southern part of Budapest which were determined over 7 years during 260 night measurements. The corrected measurements fit within 0.01" with the average value of previous Pistahegy measurements. The standard deviation of the differences due to the corrections, however, may reach 0.015" for the DOV components.

Performance Investigation of the lifetime and efficiency of solar cell using surface photovoltage (SPV) method

In this paper the optical characterisation of mono crystalline fabricated solar cells has been investigated focusing on the minority carrier flow using surface photovoltage (SPV) technique and the efficiency of the solar cells has been evaluated by means of the sun simulator analysis. A computer-controlled incidence measurement system was designed for SPV measurements based on a mini mono-chromator, which was driven by a stepper motor to various wavelengths in the spectral range of 400–1200 nm. SPV is typically measured using Standard Research 510 lock-in amplifiers. A LabVIEW interface is employed for system control and data acquisition. Every step of the measurement has been described in detail throughout the whole experimental procedure. After calculating the experimental data obtained from monocrystalline silicon solar cell measurement, the length ( L ) of the minority carrier diffusion and lifetime (?) were calculated and results derived were 92 µm and almost 3.135 µs respectively. Typically in the laboratory experiment the efficiency is found in the range of 8–12% but with our experimental data we have successfully found the efficiency as 16.05% using the Sun Simulator K3000 LAB55. The results from the experimental data has promising application to assess the quality of the solar cells that are being used.

A low-cost cryogenic temperature measurement system using Arduino microcontroller

We developed a simple, flexible, low-cost, and computer-controlled cryogenic temperature measurement system for undergraduate instructional laboratories. An Arduino microcontroller board measures the voltage across a silicon diode, which is connected to a constant circuit. We present a graphical user interface based on the open-source Processing language. The system works at a reasonable accuracy from 297.15 K (typical room temperature) down to 77 K (liquid nitrogen temperature).

Development of calcium-selective potentiometric electrode using 10,19- Bis[(octadecylcarbamoyl)methoxyacetyl]-1,4,7,13,16-pentaoxa-10,19- diazacycloheneicosane compound as ionophore

This work deals with the development of micro-size potentiometric calcium-selective electrode. A simple and rapid potentiometric method of determining calcium concentration, based on 10,19-Bis[(octadecylcarbamoyl) methoxyacetyl]- 1,4,7,13,16–pentaoxa-10,19-diazacycloheneicosane, is described. For this aim, calcium-selective polyvinylchloride (PVC) membrane was prepared by coating on the surface of solid-contact. Calcium-selective PVC membrane electrode does not contain internal reference electrode and solution. The potentiometric performance of calcium-selective PVC membrane electrode (selectivity constant, liner working range, detection limit, response time, pH working range, repeatability, lifetime, and time dependent potential decay) was determined using computer controlled measurement system in static conditions. The results showed that the calcium-selective electrode exhibited good reproducibility in calcium determination.

Electrical properties and microstructure of phase combination in BaTiO3-based Ceramics

Perovskite barium titanate (BaTiO3) ceramics are widely used in electronics industries such as capacitors, sensors and actuators. BaTiO3-based ceramics have good dielectric, ferroelectric and piezoelectric properties. BaTiO3 powder was fabricated by mixed-oxide method via a vibro-milling technique. The pellets were then placed in a high purity alumina crucible in air and sintered at 1375 °C for 1, 2, 4, 6 and 8h. X-ray diffraction technique was used to investigate phase formation of BaTiO3 ceramics. Grain size was measured by scanning electron microscopy (SEM). The computer-controlled dielectric measurement system consisted of a high precision LCR-meter. Electric field induced polarization was measured by Sawyer-Tower circuit. In this work, the effect of phase combination in BaTiO3 ceramics on electrical properties (dielectric and electric field induced polarization) and microstructure was investigated.

Electrical current measurement system for energy harvesting applications

The measurement of the dynamic power consumption is an important task in the field of energy harvesting regarding the characterization and optimization of low power systems. This paper reports on the development and characterization of a computer-controlled measurement system for the measurement of the dynamic current consumption of low power systems in a range from 100 nA to 100 μA, with a time resolution down to 1 μs.

Automated sensing of hydroponic macronutrients using a computer-controlled system with an array of ion-selective electrodes

Automated sensing of macronutrients in hydroponic solutions would allow more efficient management of nutrients for crop growth in closed hydroponic systems. Ion-selective electrodes (ISEs) are a promising approach because they can directly measure the analyte with a wide range of sensitivity and are small and portable. However, signal drift and reduced accuracy over time are major concerns with an in-line management system based on continuous immersion of ISEs in a solution. An ISE-based, computer-controlled measurement system for automatic sampling, calibration, and electrode rinsing is a viable technique to improve accuracy and precision in the determination of nutrient concentration. This study reports on development and evaluation of such a system for direct measurement of macronutrients in recirculating hydroponic solutions. The sensitivity and selectivity of PVC membrane-based ISEs fabricated with TDDA–NPOE, valinomycin, and calcium ionophore II were satisfactory for measuring NO3–N, K, and Ca concentrations in single-ion solutions over ranges typical of hydroponic solutions. However, an acceptable Mg membrane was not identified. An ISE array incorporating the selected membranes, in combination with a computer-controlled measurement system, was evaluated for the direct measurement of NO3–N, K, and Ca concentration in paprika hydroponic nutrient solutions. Using previously developed baseline correction and two-point normalization methods, ISE-measured NO3–N and K concentrations in spiked or diluted hydroponic nutrient samples were strongly related to those determined using standard laboratory instruments (R2=0.85). However, the tested Ca electrode did not provide satisfactory results due to reduced sensitivity and poor selectivity in the hydroponic solution. The approach used in this research, where a base solution is used for both referencing the baseline and rinsing electrodes and two calibration solutions are injected to implement the two-point normalization method, could be used in an automated sensing system for hydroponic nutrients in greenhouses. Additional research is required to identify ion-selective membranes for Ca and Mg ions in hydroponic solutions.

Improved Sensing Characteristics of a Novel $\hbox{Pt} \hbox{/HfTiO}_{2}\hbox{/SiC}$ Schottky-Diode Hydrogen Sensor

A novel metal-insulator-silicon carbide Schottky-diode hydrogen sensor with HfTiO2 gate insulator annealed in three different gases (N2, O2, or NO) is fabricated. Measurements are carried out at various hydrogen concentrations at high temperature using a computer-controlled measurement system. The hydrogen-sensing characteristics of the devices are studied with the help of ellipsometry, transmission electron microscopy, scanning electron microscope, energy-dispersive spectroscopy, and atomic force microscopy. Experimental results show that these sensors have high sensor output and can give significant response even at low hydrogen concentration. This work also finds that the NO-annealed sensor has the highest sensor output. When 800-ppm H2 in N2 gas is introduced, the NO-annealed sensor exhibits a high sensor output of 782% at 450°C, which is about three and six times higher than those of the O2- and N2-annealed sensors, respectively. As compared to another sensor with HfO2 gate insulator annealed in NO, the proposed NO-annealed sensor shows higher sensor output, which should be mainly attributed to the larger barrier height at the metal-insulator interface. The excellent hydrogen-sensing characteristics of this novel sensor make it very suitable for detecting hydrogen leakage, particularly in high-temperature environments.

Enhanced Sensing Performance of MISiC Schottky-Diode Hydrogen Sensor by Using HfON as Gate Insulator

MISiC Schottky-diode hydrogen sensor with HfON gate insulator fabricated by NO nitridation is investigated. The hydrogen-sensing characteristics of this novel sensor are studied by doing steady-state and transient measurements at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that this novel sensor can rapidly respond to hydrogen variation and can give a significant response even at a low H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> concentration of 48-ppm, e.g., a sensitivity of 81% is achieved at 450°C and 2.5 V, which is two times higher than its HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> counterpart. The enhanced sensitivity of the device should be attributed to a remarkable reduction of the current of the sensor before hydrogen exposure by the NO nitridation because the NO nitridation can passivate the O vacancies in the insulator and facilitate the formation of a SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interlayer to suppress the leakage current associated with high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> materials.

Effects of N 2-annealing conditions on the sensing properties of Pt/HfO 2/SiC Schottky-diode hydrogen sensor

Hafnium oxide (HfO 2) used as the gate insulator of metal-insulator-SiC Schottky-diode hydrogen sensors is annealed in nitrogen at different temperatures and durations for achieving a better performance. The hydrogen-sensing properties of these samples are compared with each other by taking measurements under various temperatures and hydrogen concentrations using a computer-controlled measurement system. The sensor response of the device is found to increase with the annealing temperature and time because higher annealing temperature and longer annealing time can enhance the densification of the HfO 2 film; improve the oxide stoichiometry and facilitate the growth of an interfacial layer to give better interface quality, thus causing a significant reduction of the current of the sensor under air ambient. The effects of hydrogen adsorption on the barrier height and conduction mechanism of the devices are also investigated.

Using virtual experiments in the teaching process

The Virtual Instrument is usually understood as real computer controlled measurement system. The control of the physical instrument, which exists in the background of the computer, may be performed using the computer keyboard, mouse and display. Wider understanding of the virtual instrumentations includes also a variety of the computer based applications for the processes modeling, instrument simulations or execution animations of the measuring systems. Presented paper try to point out to an example of using a Virtual Instrument tool (created with LabView software) in the teaching process in Sciences area. The use of LabView in a Physics lessons was illustrated by “RLC series circuit” experiment. The application was made in the frame of the three years Socrates-Comenius 2.1 project “VccSSe – Virtual Community Collaborating Space for Science Education” (no. 128989-CP-1-2006-1-RO-Comenius-C21), co-funded by the European Commission, Education and Training: School Education: Socrates: Comenius.

Improved sensing characteristics of MISiC Schottky-diode hydrogen sensor by using HfO 2 as gate insulator

Hafnium dioxide deposited by RF sputtering is used as the gate insulator of metal–insulator–silicon–carbide (MISiC) Schottky-diode hydrogen sensors. Sensors with different gate insulator thicknesses are fabricated for investigation. Their hydrogen-sensing properties are compared with each other by taking measurements at various temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that for the same insulator thickness, the HfO 2 sensor is more sensitive than its SiO 2 counterpart. This should be mainly attributed to the larger barrier-height at the Pt/HfO 2 interface which can reduce the current of the sensor before hydrogen exposure. Moreover, the sensitivity initially increases with the thickness of the HfO 2 film because a thicker oxide layer can provide a larger barrier-height reduction upon hydrogen exposure. However, further increasing the thickness of the HfO 2 dielectric beyond about 3.3 nm reduces the sensitivity, possibly due to more trapped charges in thicker high- k dielectric which can screen the effect of the polarized hydrogen layer.

Inner demagnetization factor in polymer-bonded soft magnetic composites

The inner demagnetization factor N i of polymer-bonded soft magnetic composites (PBSMC) varying in filler material and filler content C was measured, using a computer-controlled measurement system. For all materials the results show a decrease from an inner demagnetization factor close to the demagnetization factor of a single particle to N i≈0 on increasing the magnetic content C. Measurement data of a selected material were compared with a model derived from an effective medium theory using the composite's effective susceptibility and show superb accordance.

Nonlinear finite element simulation for magnetic flux leakage tester

The paper reports about the building up a computer controlled measurement system based on National Instruments Data Acquisition card and National Instruments LabVIEW software package. The aim of this research is to detect manufactured surface cracks on steels by applying a magnetic flux leakage testing method. First of all, a finite element method based on the procedure to analyze the behavior has been implemented of the measurement system under construction. One important question is the position of the sensors or of the detecting coils. The finite element procedure contains a two dimensional arrangement. First, eddy currents have been neglected, but the nonlinear characteristic of the specimen has been taken into account by a single valued function. In this paper, the developed measurement system, which is partially ready to work, and the nonlinear finite element procedures are presented as well.

A differential double-coil inductive transducer for measuring electrical conductivity

A differential system of two double-coil inductive transducers for the contactless measurement of the electrical conductivity of conducting materials has been presented. The differential system can be employed in applications that require smaller measurement uncertainty than that provided by the single-transducer system. A mathematical model of the differential system is based on the model of a single double-coil inductive transducer; in this case, a so-called processing function is defined as a ratio of voltages at the measurement coil terminals with and without the test sample. The relative differential voltage of the differential system is derived as a difference of processing functions of two single transducers and depends on a relative difference between conductivities of the test and reference samples. The conductivity of the test sample is obtained either using precalculated graphs or by numerically processing the equation of the differential voltage. In order to verify the obtained theoretical results, experimental investigations have been carried out using a computer-controlled measurement system with the differential system of the transducers. The conductivity measurements have been carried out using samples made of aluminum rods. During the measurements, the temperature of the reference sample was equal to room temperature (20 degrees C), whereas the temperature of the test sample was changed in the range of 0-20 degrees C to obtain the conductivity variation. The obtained experimental results confirmed the accuracy of the theoretical model of the differential transducer.

Measurement and control of scalar hysteresis characteristics

A computer controlled measurement system based on National Instruments Data Acquisiton card and National Insturments LabVIEW software package has been built. First, the hysteresis characteristics of the tested specimen have been simulated by Jiles-Atherton model, and simulated measurements have been performed using LabVIEW functions. This work is a preliminary study of LabVIEW and the measurement of hysteresis. The main goal is to control the magnetic flux density measured on a toroidal shaped core with a feedback controller. In this paper, the developed procedure, which is able to measure the hysteresis characteristics applying analogue and digital integrators, and to control the waveform of magnetic flux density determined from the voltage induced in the secondary coil wound on the toroidal shaped core is presented. The experience proves that the developed controller is stable and robust. This work is an initial step of the vector hysteresis measurement system.

A Comparison of MISiC Schottky-Diode Hydrogen Sensors Made by NO,$hboxN_2hboxO$, or$hboxNH_3$Nitridations

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O, and NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) are fabricated. Steady-state and transient-response measurements are carried out at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that these nitrided sensors have high sensitivity and can give a rapid and stable response over a wide range of temperature. This paper also finds that N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O provides the fastest insulator growth with good insulator quality and hence the highest sensitivity among the three nitrided samples. The N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O-nitrided sensor can give a significant response even at a low H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> concentration of 48-ppm H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300 degC, the response times of the N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O, NO, and NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -nitrided sample to the 48-ppm H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator

A quasi-static magnetic hysteresis loop measurement system with drift correction

A method to overcome the residual drift problem inherent to M-H quasi-static hysteresis loop measurements is described. The solution is based on the magnetic hysteresis symmetry properties and was implemented in a computer-controlled inductive measurement system with frequency range 3-100 MHz for straight and circular samples particularly of soft amorphous and nanocrystalline alloys. Results obtained for several samples are presented showing the ability of the method to remove the residual drift.

Establishment of a computer-controlled retroreflection measurement system at the National Metrology Institute of Turkey (UME)

In order to characterize photometric properties of retroreflectors, a fully automated retroreflector measurement system is designed in National Metrology Institute of Turkey (UME). The system is composed of a lighting projector, a goniometer, filter radiometers, 100dB transimpedance amplifiers, and 24-bit resolution analog-digital converter card with a special software. The established system provides a new calibration capability to determine the luminous intensity and retroreflection coefficients of the retroreflective materials with the expanded uncertainties of 1.07% and 1.13% (k=2), respectively. The traceability in retroreflection measurements was linked to the detector-based photometric scale of UME.