scholarly journals The Virtual Lock-in Amplifiers - Accuracy of Measurement Results in Light Transmission Experiments

2021 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
Lintang Ratri Prastika ◽  
◽  
Lili Indarti ◽  
Hendro Hendro ◽  
◽  
...  
Keyword(s):  
Light Transmission ◽  
Reference Signal ◽  
Transmission Experiment ◽  
Average Percentage ◽  
Signal Light ◽  
External Reference ◽  
Measurement Results ◽  
Turbidity Level ◽  
Accuracy Of Measurement ◽  
Lock In

This research focuses on the analysis of the measurement result of the virtual lock-in amplifier (virtual-LIA) in the light transmission experiment as the trial step of developing the virtual-LIA. The virtual-LIA used in this research is designed by using the Vernier sensor DAQ as the data acquisition and the LabVIEW as the programming media. The design of virtual-LIA is based on the mathematical operations of LIA. The type of virtual-LIA is a single phase with the capabilities to process the external reference signal. Light transmission experiments are carried out using formazin polymer suspension with turbidity level of 3000 NTU, 3500 NTU, and 4000 NTU as the medium in which light is passed. The accuracy of the measurement results is known by comparing the results of virtual-LIA with real-LIA SR510. The experiments are also carried out in bright and darkroom conditions to determine the ability of virtual-LIA in reducing noise signals. Based on the experiment, the results obtained that the measurement accuracy of the virtual-LIA developed is above 94% compared to the LIA SR510. Virtual-LIA could measure small signals with and without noise with the average percentage of differences measured between dark and bright conditions is 0.54%.

The Study of Four-Position North Seeking System under Vibration Environment

2014 ◽  
Vol 668-669 ◽  
pp. 990-993
Author(s):  
Ming Hui Zong ◽  
Deng Hua Li
Keyword(s):  
Fiber Optic ◽  
Reference Signal ◽  
Vibration Signal ◽  
Pi Controller ◽  
Angle Sensor ◽  
The North ◽  
External Reference ◽  
Tilt Sensor ◽  
The Relationship ◽  
Better Than

In order to develop north seeking system with strong anti-interference ability, the influence caused by the swaying base on the performance of north seeker was investigated. The influence of sinusoidal signal of gyros and tilt sensor's output was analyzed based on four-position north seeking system which was consisted of a single axis gyro and a tilt sensor. Fiber optic gyros and tilt sensor are interference by the same vibration signal, according to the relationship between the output signal of gyro and the angle sensor, a PI controller was designed to compensate the gyro's output error. This real time compensation can effectively improve the north seeking accuracy and speed without complicated calculation or external reference signal. The north seeking accuracy is better than 0.03o. Simulation and actual north seeking result proved that this method significantly improves the north seeking performance in vibrant environment.

On the Methods for Measuring High Temperature Resistivity of Glass

2016 ◽  
Vol 680 ◽  
pp. 39-43
Author(s):  
Ying Liang Tian ◽  
Mei Zhang ◽  
Yong Ming Li ◽  
Feng Wang ◽  
Jing Ting Yang
Keyword(s):  
High Temperature ◽  
Test Procedure ◽  
Aluminosilicate Glass ◽  
Voltage Measurement ◽  
Advantages And Disadvantages ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
High Alkali ◽  
Increasing Temperature ◽  
Temperature Resistivity

This paper described three methods for measuring high temperature resistivity of glass including their basic principles, advantages and disadvantages so as to provide a reference for measurement. The effects of electrode and voltage on high temperature resistivity were studied. Accuracy of measurement results of plate electrodes is better than wire electrodes. The resistivity of molten glass decreased with increasing AC voltage. Measurement results are stable when the voltage is less than 10 V, but when the voltage exceeds than 40 V, Joule heating effect will be generated resulting in smaller measurement values. In addition, high alkali aluminosilicate glass as object is used to introduce test procedure of temperature resistivity and explore the relationship between high temperature resistivity and alkali metal. Results show that high alkali aluminosilicate glass resistivity decreases with increasing temperature, and the effect of K2O on high tempearature resistivity is more pronounced.

Measurement of small values of hydrostatic pressure difference / Pomiar małych wartości różnicy ciśnień hydrostatycznych

2012 ◽  
Vol 57 (1) ◽  
pp. 157-167
Author(s):  
Krzysztof Broda ◽  
Wiktor Filipek
Keyword(s):  
Hydrostatic Pressure ◽  
Pressure Distribution ◽  
Atmospheric Pressure ◽  
Free Water ◽  
Reynolds Numbers ◽  
Measurement Results ◽  
Order Of Magnitude ◽  
Hydraulic Gradients ◽  
Accuracy Of Measurement ◽  
Definition Of

In order to describe the fluid flow through the porous centre, made of identical spheres, it is necessary to know the pressure, but in fact - the pressure distribution. For the flows in the range that was traditionally called laminar flow (i. e. for Reynolds numbers (Bear, 1988; Duckworth, 1983; Troskolański, 1957) from the range 0,01 to 3) it is virtually impossible with the use of the tools directly available on the market. Therefore, many scientists who explore this problem have concentrated only on the research of the velocity distribution of the medium that penetrates the intended centre (Bear, 1988) or pressure distribution at high hydraulic gradients (Trzaska & Broda, 1991, 2000; Trzaska et al., 2005). It may result from the inaccessibility to the measurement methods that provide measurement of very low hydrostatic pressures, such as pressure resulting from the weight of liquid located in the gravitational field (Duckworth, 1983; Troskolański, 1957). The pressure value c. 10 Pa (Troskolański, 1957) can be generated even by 1 mm height difference between the two levels of the free water surface, which in fact constitutes the definition of gauging tools of today measuring the level of the hydrostatic pressure. Authors proposed a method of hydrostatic pressure measurement and devised a gauging tool. Then a series of tests was conducted aiming at establishing what is the influence of various factors, such as temperature, atmospheric pressure, velocity of measurement completion, etc. on the accuracy and method of measurements. A method for considerable reduction of hysteresis that occurs during measurement was also devised. The method of measurement of small hydrostatic difference measurements allows for the accuracy of measurement of up to 0.5 Pa. Measurement results can be improved successfully by one order of magnitude, which for sure would entail necessary temperature stabilization of the tool. It will be more difficult though to compensate the influence of atmospheric pressure on the measurement process.

scholarly journals INVESTIGATION OF MEASUREMENT ACCURACY IN DETERMINING THE MASS OF BULK MATERIALS

2020 ◽  
Vol 8 (2) ◽  
pp. 42-48
Author(s):  
Galina V. Simonova
Keyword(s):  
Bulk Density ◽  
Fractional Composition ◽  
Bulk Material ◽  
Indirect Measurement ◽  
Bulk Materials ◽  
Technological Processes ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
Fractional Control

The article is devoted to the assessment the error in determining the mass of a sample bulk materials when using the values of their bulk density. Precisely the accuracy of measurement results is necessary in many fields of activity to ensure the efficiency and safety of technological processes, as well as improving product quality. The relevance of this work is associated with the assessment of the inevitable deviations of the bulk density the same material in a given volume as a result of an uncontrolled fractional composition of a sample of bulk material. As a consequence of these deviations, an error arises in determining the mass of a sample of a given volume, even if this volume is an uniquely determined quantity. The paper presents the results of studies of the influence of the fractional composition of bulk materials on the determination of their mass in the indirect measurement method. A significant effect of the fractional composition of bulk materials on the error of the indirect method for determining the mass of the sample was revealed. It is shown, that there is a need for fractional control of the composition of bulk materials in the development of control operations of technological processes, as well as restrictions on the use of bulk density with increased requirements for the accuracy of determining the mass of a sample.

Development of Lock-In Infrared Thermography Techniques for Quantitative Nondestructive Evaluations

2007 ◽  
Author(s):  
Takahide Sakagami ◽  
Shiro Kubo
Keyword(s):  
Temperature Change ◽  
Fourier Coefficients ◽  
Reference Signal ◽  
Temperature Data ◽  
Random Loading ◽  
Material Loss ◽  
Nondestructive Evaluations ◽  
Significant Temperature ◽  
Lock In ◽  
Self Reference

In this paper, lock-in thermography techniques for quantitative nondestructive evaluations developed by the present authors are reviewed. Self-reference lock-in thermography was developed for remote nondestructive testing of fatigue cracks. This technique is based on the measurement of thermoelastic temperature change due to stress change. Cracks can be identified from significant temperature change observed at crack tips due to the stress singularity. For accurate measurement of the thermoelastic temperature change under random loading, a self-reference lock-in data processing technique was developed, in which a reference signal was constructed by using the temperature data simultaneously taken at a remote area. Thermoelastic temperature change in a region of interest was correlated with that at the area for reference signal construction. It enabled us to measure the relative stress distribution under random loading without using any external loading signal. The self-reference lock-in thermography was applied for fatigue crack identification in welded steel plate specimens and actual steel structures. It was found that significant temperature change was observed at the crack tip in the self-reference lock-in thermal image, demonstrating the feasibility of the proposed technique. Lock-in thermography technique was also applied to quantitative nondestructive evaluation of material loss defects. Transient temperature data under pulse or step heating were measured by infrared thermography. Temperature data were processed by the lock-in analysis scheme based on the Fourier series expansion, in which Fourier coefficients synchronizing with sine and cosine waves were correlated with defect parameters. Experimental investigations were conducted using steel samples with artificial material loss defects. It was found that the defect parameters can be quantitatively determined from the Fourier coefficients, demonstrating the feasibility of the proposed technique.

Study on Phase Shifting Algorithm and System of White Light Interference

2014 ◽  
Vol 889-890 ◽  
pp. 749-754
Author(s):  
Lin Juan Deng ◽  
Yu Xia Fu ◽  
Xiao Yu Cai ◽  
Yuan Li ◽  
Li Hua Lei ◽  
...  
Keyword(s):  
White Light ◽  
Phase Shifting ◽  
Light Phase ◽  
Traceability System ◽  
Light Interference ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
White Light Interference ◽  
Phase Shifting Method ◽  
Definition Of

The white-light interferometry (WLI) has been widely used in 3D topography measurement. This paper introduces a white light phase shifting method for interferometry with the combination of Hariharan phase shifting and WLI. A micro/nanolevel mechanic system was designed and built for the experiments. To verify system accuracy and feasibility, a 100nm step height standard was measured by the designed system and the metrological nanomeasurement machine (NMM). Results of 102.7nm and 102.5nm are obtained respectively. En value of 0.14 is calculated, demonstrating the reliability of result measured by the system. Based on classic nanoquantity traceability system, the measurement results can effectively traced back to the definition of nanometer magnitude, which can improve the accuracy of measurement.

Low-cost, digital lock-in module with external reference for coating glass transmission/reflection spectrophotometer

2003 ◽  
Vol 14 (5) ◽  
pp. 551-557 ◽  
Author(s):  
R Alonso ◽  
F Villuendas ◽  
J Borja ◽  
L A Barrag n ◽  
I Salinas
Keyword(s):  
Low Cost ◽  
External Reference ◽  
Lock In

An Investigation of Various Factors Affecting Measurement Accuracy of the Tekscan Seat Pressure System

1996 ◽  
Vol 40 (20) ◽  
pp. 1036-1040 ◽  
Author(s):  
Hongzheng Lu ◽  
Gang Lin
Keyword(s):  
Measurement Error ◽  
Contact Area ◽  
Contact Time ◽  
Measurement Accuracy ◽  
Time Interval ◽  
Pressure System ◽  
Factors Affecting ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
Pressure Measurement System

This study investigated the following factors affecting the measurement accuracy of the seat pressure measurement system made by TekScan, Inc.: (a) contact time; (b) contact area; (c) the amount of force applied on the pressure mat at the time of calibration and at measurement; and (d) the consistency of contact time before calibration and measurement, and the time interval between calibration and measurement. Results show that the above factors significantly affect the accuracy of measurement. The measurement error can be limited by controlling the contact time for both calibration and measurement to 2 minutes, and controlling the contact area and applied force equally at calibration and measurement.

scholarly journals Investigation Into the Accuracy of 3D Surface Roughness Characteristics

2014 ◽  
Vol 51 (2) ◽  
pp. 55-59 ◽  
Author(s):  
M. Kumermanis ◽  
J. Rudzitis ◽  
N. Mozga ◽  
A. Ancans ◽  
A. Grislis
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Measuring Time ◽  
3D Surface ◽  
3D Surface Roughness ◽  
Spark Erosion ◽  
Measurement Results ◽  
Data Points ◽  
Accuracy Of Measurement

Abstract The existing standards for surface roughness cover only two dimensions, while in reality this is three-dimensional (3D). In particular, the 3D surface roughness parameters are important for solving the contact surface mechanics problems as related to the accuracy of 3D surface roughness characteristics. One of the most important factors for determination of 3D characteristics is the number of data points (NDP) on the x- and y-axes (i.e. in cut-off length). The NDP has a profound effect on the accuracy of measurement results, measuring time and volume of the output data (especially along the y-axis, where the NDP is identical to the number of parallel profiles). At a too small NDP the results will be incorrect and with too broad scatter, while a too large NDP - though not enlarging the range of basic information - considerably increases the measuring time. Therefore, the aim of the work was to find the optimal NDP for such surface processing methods as grinding, spark erosion and shot methods of surface treatment.

scholarly journals The development of healthcare mobile robot for helping medical personnel in dealing with COVID-19 patients

2021 ◽  
Vol 22 (3) ◽  
pp. 1379
Author(s):  
Nova Eka Budiyanta ◽  
Linda Wijayanti ◽  
Widodo Widjaja Basuki ◽  
Harlianto Tanudjaja ◽  
V. Budi Kartadinata
Keyword(s):  
Robot Control ◽  
Medical Personnel ◽  
Test Results ◽  
Robotic Technology ◽  
Development Method ◽  
Average Percentage ◽  
Measurement Results ◽  
Feasibility Test ◽  
Control Distance ◽  
Very High

<span lang="EN-US">Coronavirus disease (COVID-19) pandemic has succeeded in shaking the whole world. This situation requires medical personnel to work extraordinarily to treat COVID-19 patients with very high risk of transmission. For this reason, this study aimed to helping medical personnel handle COVID-19 patients through robotic technology. The development method in this study is proposed as a way to develop robots to serve patients in isolation rooms controlled at a distance away from other rooms. From technical testing, the movement of the robot with a load of 12.59 kg only experienced a speed slowdown which was not too significant, namely at 0.43s with an average percentage of slowdown of 8.96%. The accuracy of the proximity sensor testing is close to perfect with an accuracy percentage of 99.62%. The robot control distance was monitored and running well. Also, the increase in motor temperature is not too large, supported by measurement results of 32.13%. From non-technical testing, based on the test results of the feasibility test of all respondents with 25 indicators reached a feasibility level of 91.46%. In other words, healthcare mobile robots developed for helping medical personnel in dealing with COVID-19 patients are very feasible to be applied in hospitals.</span>

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