Aspects Of Instrument Design Research Articles

Dempster's descendants-The core of the development of mass spectrometry.

The work of Arthur Dempster generally has been considered significant but of less importance in the growth of mass spectrometry than that of Francis Aston, and as essentially limited to the pre-WW II era. The development of mass spectrometry, however, as distinct from nuclear science, was shaped far more by Dempster than by Aston. This influence is seen in several aspects of instrument design and practice, and it has continued into the 21st century.

Leveraging ultraviolet photodissociation and spectroscopy to investigate peptide and protein three-dimensional structure with mass spectrometry.

Recent advances in mass spectrometry and lasers have facilitated the development of novel experiments combining the benefits of both technologies. This minireview focuses on the coupling of visible/ultraviolet photons with mass spectrometry for analysis of peptide and protein three-dimensional structure. Practical aspects of instrument design and the relationship between experiment and theory are discussed. Experiments utilizing spectroscopy, action spectroscopy, excitation energy transfer, photodissociation, and photoactivated radical chemistry are described. The strengths and weaknesses of each approach are discussed in relation to the type of information typically obtained. A significant body of data suggests that under appropriate source conditions, kinetically trapped structures are observed in these experiments rather than true gas phase minima, suggesting retention of solution phase structural features is possible. Further refinement and exploration of these methods promises to accelerate protein structure discovery in the near future.

Use of aircraft to probe the troposphere

This paper seeks to give an overview of atmospheric research aircraft, offer the reader examples from current research platforms and provide key reference material for further study. The value of aircraft studies to atmospheric measurement science will be discussed in comparison with other measurement research platforms and the capabilities and deficiencies of the different platforms will be considered. The paper will then summarise the key aspects of instrument design that are critical for aircraft operations. Sample inlets are integral to successful sampling from aircraft platforms and these will be discussed in detail, focussing on sticky gases, radicals and aerosol particles and clouds. The remainder of the paper will focus on the planning of field missions and offer some examples of major results from aircraft experiments.

Automated Flow-Injection Instrument for Chemiluminescence Detection Using a Low-Cost Photodiode Detector: An Interdisciplinary Project in Chemical Instrumentation, Graphical Programming, Computer Interfacing, and Analytical Chemistry

This work is concerned with the design, construction, automatic control, and optimization of a flow injection analysis (FIA) instrument with chemiluminescence (CL) detection. The project proceeds in three stages: the construction of the detector, the construction and control of the flow system, and the chemical measurements. The light detector is based on a low-cost commercially available photodiode. Control of the flow system and data acquisition is performed through an interface card controlled by the LabVIEW software tool. In developing the detector and the flow system, students were acquainted with different aspects of instrument design and control, such as light detectors, operational amplifiers, analog and digital filtering, computer interfacing (digital-to-analog converters, analog-to-digital converters, digital input–output), and graphical programming. The apparatus developed was used to optimize the chemical and instrumental variables of a FIA–CL method for the quantitative determination of Co(II).

On-line compensation in a digital Coriolis Mass Flow meter

For many years it has been demonstrated that the use of digital technology, particularly embedded microprocessors, can improve flowmeter performance in various ways (e.g. temperature compensation, elimination of drift, generation of engineering units, diagnostics). A self-validating or SEVA sensor uses in-built processing power to generate generic metrics of measurement quality, based on on-line uncertainty. This uncertainty includes all factors effecting the on-line measurement, including diagnostics but also manufacturing aspects such as the components used and the characterisation procedure. This paper describes a prototype SEVA coriolis mass flow meter transmitter built primarily from digital components, which provides compensation for both faults and manufacturing limitations. A technique to compensate for drift and imbalance in the transmitter front-end circuitry is described in detail. The prototype has been developed using a hardware/software co-design approach in which virtually all aspects of instrument design are described in software, but which can be implemented flexibly in either hardware or software according to economic requirements. This approach offers manufacturers the opportunity of incorporating the latest components into their products rapidly in order to remain competitive.

Geophysical instrumentation in China: A review of higher education and research

Geophysics is based on observations, and innovations in geophysical instrumentation that enable explorationists to look more precisely into the earth in the search for oil and minerals. Due to tremendous advances in electronics and computer sciences, geophysical instrumentation has become highly sophisticated and the development of improved instrumentation involves cross‐disciplinary skills including geophysics, electronics, computer engineering, mechanics, signal processing, systems engineering, and artificial intelligence. Few can master all aspects of instrument design and, thus, we must consider three questions.

Evaluation of an Infrared Open-Path Spectrometer Using an Exposure Chamber and a Calibration Cell

This study evaluated the use of a controlled exposure chamber and calibration cell to investigate the performance of open-path remote sensing instruments for workplace monitoring of pollutants. An open-path infrared spectrometer was deployed in a chamber, and a range of homogeneous air concentrations were generated using the tracer gas sulfur hexafluoride (SF6). Open-path measurements were compared with point-sample measurements taken along the beam and analyzed using an infrared (IR) and electron capture detector (ECD). A five-compartment calibration cell placed in the optical path was used to simulate heterogeneous concentrations of pollutants. Fifteen concentration patterns were created by injecting different volumes of SF6 into each compartment. Open-path spectrometer measurements were compared with compartment concentrations measured using an ECD. Results indicated that stable homogeneous and heterogeneous concentrations of SF6 were generated in the controlled exposure chamber and five-compartment calibration cell, respectively. Overall, individual open-path measurements were within 20% of point samples measured with the IR and ECDs. The open-path spectrometer measurements had a consistent positive bias of about 12%. Exposure chamber experiments uncovered remote sensing instrument design aspects that could adversely impact its use for indoor monitoring. The weight and size of the instrument make it useable only in a fixed position, thus limiting spatial coverage of the beam in a room. The instrument components were not air-tight, resulting in overestimation of some open-path concentrations. A controlled test chamber and a long calibration cell placed in the optical path are useful tools for evaluating a variety of open-path spectrometer instrument performance issues relevant to industrial hygiene monitoring.

A Lecture/Laboratory Course on Microcomputer-Based Medical Instrumentation

Most existing courses on computers in medicine study applications of minicomputers or large-scale mainframes. These courses typically emphasize data-base management or computer simulation of biological systems. At the University of Wisconsin-Madison, our course has evolved away from these applications and toward design of microcomputer-based medical instrumentation. To support this course, we have developed a textbook on this topic and a set of ten laboratory experiments that give the student hands-on experience with both hardware and software aspects of instrument design.

Operational Aspects of Instrument Design

Operational Aspects of Instrument Design