Meteorological Measurement Systems

2001 ◽  
Author(s):  
Fred V. Brock ◽  
Scott J. Richardson
Keyword(s):  
Dynamic Performance ◽  
Measurement Systems ◽  
Sensor Performance ◽  
Performance Specifications ◽  
Meteorological Measurement ◽  
Design Type ◽  
Static Sensitivity ◽  
And Function ◽  
Logical Functions ◽  
Source Of Error

This book treats instrumentation used in meteorological surface systems, both on the synoptic scale and the mesoscale, and the instrumentation used in upper air soundings. The text includes material on first- and second-order differential equations as applied to instrument dynamic performance, and required solutions are developed. Sensor physics are emphasized in order to explain how sensors work and to explore the strengths and weaknesses of each design type. The book is organized according to sensor type and function (temperature, humidity, and wind sensors, for example), though several unifying themes are developed for each sensor. Functional diagrams are used to portray sensors as a set of logical functions, and static sensitivity is derived from a sensor's transfer equation, focusing attention on sensor physics and on ways in which particular designs might be improved. Sensor performance specifications are explored, helping to compare various instruments and to tell users what to expect as a reasonable level of performance. Finally, the text examines the critical area of environmental exposure of instruments. In a well-designed, properly installed, and well-maintained meteorological measurement system, exposure problems are usually the largest source of error, making this chapter one of the most useful sections of the book.

Overview

2001 ◽  
Author(s):  
Fred V. Brock ◽  
Scott J. Richardson
Keyword(s):  
Data Storage ◽  
Dynamic Performance ◽  
Quantitative Information ◽  
Essential Elements ◽  
Static Characteristic ◽  
Data Display ◽  
Analog To Digital ◽  
Storage Devices ◽  
High Quality Information ◽  
Static Sensitivity

Measurements are required to obtain quantitative information about the atmosphere. Elements of a good measurement system, one that produces high-quality information, are briefly described in the following sections. All of these items are, or should be, of concern to everyone who uses data. None may be safely delegated, in their entirety, to those who have little or no interest in the ultimate use of the data. An instrument is a device containing at least a sensor, a signal conditioning device, and a data display. In addition, the instrument may contain an analog-to-digital converter, data transmission and data storage devices, a microprocessor, and a data display. The sensor is one of the essential elements because it interacts with the variable to be measured (the measurand), and generates an output signal proportional to that variable. At the other end of this chain, a data display is also essential, for the instrument must deliver data to the user. To understand a sensor, one must explore the physics of the sensor and of sensor interaction with the measurand. There is a wide variety of sensors available for measuring pressure, temperature, humidity, and so on, and this text discusses each individually. Therefore, each chapter must deal with many different physical principles. Sensor performance can be described by reference to a standardized set of performance definitions. These characteristics are used by manufacturers to describe instruments and as purchase specifications by buyers. Static characteristics are those obtained when the sensor input and output are static (i.e., not changing in time). Static sensitivity is an example of a static characteristic and is particularly useful in sensor analysis. When raw sensor output is plotted as a function of the input, the slope of this curve is called the static sensitivity. Relating static sensitivity to fundamental physical parameters is a systematic way of revealing sensor physics and leads to an understanding of the sensor and of how to improve the design. Dynamic characteristics are a way of defining a sensor response to a changing input. The most widely known dynamic performance parameter is the time constant, discussed in chap. 6.

scholarly journals Automated Evaluation of Dynamic Performance of Impulse Voltage Measurement Systems

2015 ◽  
Vol 575 ◽  
pp. 012011
Author(s):  
L C Faria ◽  
E C Silva ◽  
M T Silva ◽  
C R H Barbosa ◽  
L C Azevedo
Keyword(s):  
Dynamic Performance ◽  
Voltage Measurement ◽  
Measurement Systems ◽  
Automated Evaluation ◽  
Impulse Voltage

Lightweight Engineering of Military Vehicles Through Requirements Analysis and Function Integration

2009 ◽  
Author(s):  
Jonathan R. A. Maier ◽  
James M. McLellan ◽  
Gregory Mocko ◽  
Georges M. Fadel ◽  
Mark Brudnak
Keyword(s):  
Dynamic Performance ◽  
The United States ◽  
Requirements Analysis ◽  
United States Department ◽  
Modeling Framework ◽  
Military Vehicles ◽  
Lightweight Engineering ◽  
Function Integration ◽  
Logistic Support ◽  
And Function

The trend toward lighter-weight vehicles in the private sector has been pushed by demands to improve fuel economy, improve dynamic performance, and reduce material and transportation costs. The same demands exist and are even more acute for military vehicles. The reduction of weight across a military vehicle platform can affect hundreds of thousands of vehicles with dramatic ramifications for military budgets, logistic support, deployment time and cost, and other factors critical to national defense. In this paper we report on methods developed for requirements analysis and function integration based on a modeling framework (developed in previous work) which captures requirements, functions, working principles, components, component parameters, test measures, and tests. We also show that the problem of assigning the mass of individual components to requirements is not solvable in practice. The methods are demonstrated using a case study of the United States Department of Defense Family of Medium Tactical Vehicles (FMTV).

Measurement of Outgassing in a Vacuum Environment

2005 ◽  
Vol 277-279 ◽  
pp. 831-837
Author(s):  
Yong Hyeon Shin ◽  
Seung Soo Hong ◽  
In Tae Lim ◽  
J.H. Kim ◽  
Dae Jin Seong ◽  
...  
Keyword(s):  
Mass Loss ◽  
Production Process ◽  
Measurement Method ◽  
Suitable Method ◽  
Nano Technology ◽  
Loss Measurement ◽  
Measurement Systems ◽  
And Function

Outgassing, the evolution of gas from the material in a vacuum, is not only a source of micro contamination in a semiconductor or the flat display panel production process, but it also a limitation factor in the ultra clean process of nano-technology. The outgassing from the materials of satellites and spacecrafts must be controlled for increased safety and function because space is also a vacuum environment. Several methods are used in outgassing measurement in general, but there is no one method suitable for obtaining all outgassing data. The most suitable method for a particular application must be chosen by the experimenter or user. Three types of outgassing measurement systems were fabricated and characterized, ‘Throughput method,’ ‘Rate of Rise method’ and ‘Mass Loss Measurement method’. The outgassing rates of many kinds of materials were measured and characterized using these systems.

scholarly journals Design, inverted vat photopolymerization 3D printing, and initial characterization of a miniature force sensor for localized in vivo tissue measurements

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Shashank S. Kumat ◽  
Panos S. Shiakolas
Keyword(s):  
Viscoelastic Properties ◽  
Regression Coefficient ◽  
Force Sensor ◽  
Relaxation Data ◽  
Sensor Performance ◽  
Human Forearm ◽  
Performance Specifications ◽  
Voigt Model ◽  
Viscoelastic Coefficient

Abstract Background Tissue healthiness could be assessed by evaluating its viscoelastic properties through localized contact reaction force measurements to obtain quantitative time history information. To evaluate these properties for hard to reach and confined areas of the human body, miniature force sensors with size constraints and appropriate load capabilities are needed. This research article reports on the design, fabrication, integration, characterization, and in vivo experimentation of a uniaxial miniature force sensor on a human forearm. Methods The strain gauge based sensor components were designed to meet dimensional constraints (diameter ≤3.5mm), safety factor (≥3) and performance specifications (maximum applied load, resolution, sensitivity, and accuracy). The sensing element was fabricated using traditional machining. Inverted vat photopolymerization technology was used to prototype complex components on a Form3 printer; micro-component orientation for fabrication challenges were overcome through experimentation. The sensor performance was characterized using dead weights and a LabVIEW based custom developed data acquisition system. The operational performance was evaluated by in vivo measurements on a human forearm; the relaxation data were used to calculate the Voigt model viscoelastic coefficient. Results The three dimensional (3D) printed components exhibited good dimensional accuracy (maximum deviation of 183μm). The assembled sensor exhibited linear behavior (regression coefficient of R2=0.999) and met desired performance specifications of 3.4 safety factor, 1.2N load capacity, 18mN resolution, and 3.13% accuracy. The in vivo experimentally obtained relaxation data were analyzed using the Voigt model yielding a viscoelastic coefficient τ=12.38sec and a curve-fit regression coefficient of R2=0.992. Conclusions This research presented the successful design, use of 3D printing for component fabrication, integration, characterization, and analysis of initial in vivo collected measurements with excellent performance for a miniature force sensor for the assessment of tissue viscoelastic properties. Through this research certain limitations were identified, however the initial sensor performance was promising and encouraging to continue the work to improve the sensor. This micro-force sensor could be used to obtain tissue quantitative data to assess tissue healthiness for medical care over extended time periods.

Influence of Acoustic Noise on the Dynamic Performance of MEMS Gyroscopes

2007 ◽  
Author(s):  
Simon Castro ◽  
Robert Dean ◽  
Grant Roth ◽  
George T. Flowers ◽  
Brian Grantham
Keyword(s):  
Acoustic Noise ◽  
Low Cost ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Inertial Measurement ◽  
Mems Gyroscope ◽  
Measurement Systems ◽  
Mems Gyroscopes ◽  
Mems Technology ◽  
Measurement Units

Advances in MEMS technology have resulted in relatively low cost gyroscopes and accelerometers and, correspondingly, inexpensive inertial measurement systems. This has opened up the field of applications for inertial measurement units (IMUs) and they are currently being proposed for use in a wide variety of possible applications, with environmental conditions ranging from mild to harsh. Of particular interest in this study are MEMS gyroscopes, which are based upon vibratory, rather than rotational, designs and are especially susceptible to the effects of acoustic noise, as compared to conventional gyroscopes. This is particularly true for certain applications. For example, in some aerospace environments, noise levels can be greater than 120 dB and extend over a frequency range greater than 20 kHz. Output signals can be overwhelmed by such effects, becoming extremely contaminated and noisy and, can even be completely saturated. So, it is important to develop an understanding of the influence of high levels of noise on MEMS gyroscope performance and to develop methodologies to mitigate such effects. In the present investigation, a series of experimental studies were conducted for a variety of MEMS gyroscope designs. Each unit was exposed to a range of acoustic noise amplitudes and frequencies. The output signals were recorded and analyzed. The results are presented and discussed in detail. Strategies for mitigating such effects were identified and tested. Those results are also discussed in detailed.

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