207 Matching Results

Search Results

Microwave Attenuation Standards and Measurements

Description: Report discussing microwave attenuation measurement methods and standards. In addition, a relatively new and more precise way of representing and analyzing an attenuation measurement is presented. This in turn permits more rigorous definitions and error analyses than were previously possible. The referral of microwave attenuation measurements to standards operating at lower frequencies is discussed with particular attention to the errors in the referral processes as well as the errors in the standards themselves. Desirable characteristics are listed for attenuators which are suitable for calibration. Measurement methods are classified and described. Comments are made on the accuracy and convenience of various methods, and references are given which cover most of the basic and important research in this field. Key words: Microwave, attenuation, measurements, standards, tutorial.
Date: April 3, 1967
Creator: Beatty, Robert W.
Partner: UNT Libraries Government Documents Department

Microwave Impedance Measurements and Standards

Description: Report presenting a survey and discussion of well-known microwave impedance measurement techniques. The discussion includes an introduction which emphasizes basic concepts and reflection coefficient-voltage standing-wave ratio relationships. Sources of error in the various measurement techniques are discussed and methods to reduce errors are presented. Methods using rotating loops and resonance lines are included and a brief discussion of microwave impedance standards is given.
Date: August 12, 1965
Creator: Beatty, Robert W.
Partner: UNT Libraries Government Documents Department

Hydrogen Stark Broadening Calculations With the Unified Classical Path Theory

Description: Report discussing the case of upper and lower state interaction introduced by a unified theory using a more compact tetradic notation. The general result is then applied to the Stark broadening of hydrogen. The thermal average of the time development operator for upper and lower state interaction is presented. A simple technique for evaluating the Fourier transform of the thermal average has been developed. The final calculations based on the unified theory and on the one-electron theory are compared with measurements in the high and low electron density regime.
Date: May 1970
Creator: Vidal, C. R.; Cooper, J. & Smith, E. W.
Partner: UNT Libraries Government Documents Department

Vibration-Rotation Structure in Absorption Bands for the Calibration of Spectrometers From 2 to 16 Microns

Description: Reports discussing bands of common gases that have been tabulated and remeasured wherever necessary from 2 to 16 microns to obtain an accuracy of about 0.03 cm-1 throughout the region and to provide good calibrating points at frequent intervals. Some 600 rotation-vibration lines are illustrated in 20 spectrograms and wavenumbers are listed in companion tables with considerable intercomparison with worthy data obtained in other laboratories. The absorption bands were remeasured or calibrated by using either a precisely graduated grating circle or standard atomic lines with the fringe system formed by a Fabry-Perot interferometer. Characteristic features of the individual bands are discussed briefly and references to other publications are given. The substances used for calibration include H2O, CO2, CO, HCl, HBr, NH3, C2H2, CH4, N2O, and polystyrene film.
Date: June 21, 1960
Creator: Plyler, Earle K.; Danti, Alfred; Blaine, L. R. & Tidwell, E. D.
Partner: UNT Libraries Government Documents Department

A High-Dispersion Spectral Analysis of the Ba II Star HD 204075 (ζ Capricorni)

Description: Report discussing a double differential curve of growth analysis for the Ba II star S Capricorni. Both the sun and � Virginis (G9 II-III) were used as comparison stars. The observational material consists of equivalent widths, central depths, and half-widths for 1100 spectral lines measured on direct-intensity tracings of plates obtained by J. L. Greenstein at the coude focus of the 200-in telescope. The plates cover the spectral regions 3880-4825 A and 5100-6720 A at reciprocal dispersions of 2.3 and 3.4 A/mm, respectively. Atmospheric abundances have been derived for 37 elements.
Date: March 1971
Creator: Tech, Jack L.
Partner: UNT Libraries Government Documents Department

Infrared Spectroscopy of Carbohydrates: A Review of the Literature

Description: Report presenting of survey of the literature on the infrared spectroscopy of carbohydrates in order to assemble and systematize information in this field. Discusses principles and instrumentation, sampling techniques, comparison of samples, and the interpretation of the spectra. In addition, examples are discussed of the use of infrared spectra for qualitative and quantitative purposes and in the determination of structure. Special techniques are briefly described.
Date: June 1968
Creator: Tipson, R. Stuart
Partner: UNT Libraries Government Documents Department

Survey of Micromanometers

Description: This survey is concerned with instrumentation for measuring pressures from about 0.001 to 50mm of mercury (0.13 to 6650 Nm-2), described in publications during the years 1900-1968. U-tube micromanometers and diaphragm-capacitance gages are treated in considerable detail. Other instrumentation described includes gas column manometers; elastic element micromanometers with optical, inductance, resistance wire, strain gage, and vacuum tube transducers; piston gages; vane gages; and centrifugal micromanometers. The measurement of dynamic pressure, atmospheric pressure oscillations, low vapor pressure, and calibration techniques are discussed. Schematic diagrams of approximately 70 instruments are included. References to the sources of information and available performance data are given.
Date: 1970
Creator: Brombacher, W. G.
Partner: UNT Libraries Government Documents Department

Corrosion and Protection of Steel Piles in a Natural Seawater Environment

Description: From Introduction: "This paper describes some results of the first eight years of a fifteen year program in which a variety of coating and catholic protection systems are evaluated on their ability to protect steel piles in offshore conditions at Dam Neck, Virginia. It includes a description of the methods used in the evaluation and the results found on these systems."
Date: June 1977
Creator: Escalante, E.; Iverson, W. P.; Gerhold, W. F.; Sanderson, B. T. & Alumbaugh
Partner: UNT Libraries Government Documents Department

The Measurement of Lumped Parameter Impedance: A Metrology Guide

Description: Scope of the Guide: "This guide is not all-inclusive of the subject of impedance measurement and the reader should understand at the outset what he can or cannot expect to find. To help in establishing the bounds of subject matter included, consider the ideal impedance-measuring instrument as having the following the characteristics and capabilities: (1) unrestricted frequency range (2) unrestricted impedance range (3) unrestricted capabilities with respect to bias, ambience, applied power, etc. (4) error free (5) performs measurements instantaneously (6) zero acquisition cost (7) zero operating cost."
Date: June 1974
Creator: Jones, R. N. & Anson, W. J.
Partner: UNT Libraries Government Documents Department

Tables of Spectral-Line Intensities: Part 1 - Arranged by Elements

Description: From Abstract: "Comparisons with other other intensity measurements in individual spectra indicate that the National Bureau of Standards spectral-line intensities may have average errors of 20 percent, but first of all they provide uniform quantitative values for the seventy chemical elements commonly determined by spectrochemists. These data are presented by element in part I, and all 39000 observed lines are given in order of wavelength in part II."
Date: May 1975
Creator: Meggers, William F.; Corliss, Charles H. & Scribner, Bourdon F.
Partner: UNT Libraries Government Documents Department

Visual Range: Concepts, Instrumental Determination, and Aviation Applications

Description: From Abstract: "This document is a review of the principles, procedures, and instruments used in the measurement of visual range. The fundamental concepts of the visual range of the objects and lights are discussed. The principles of operation of the several classes of atmospheric attenuation meters are reviewed and representative instruments are described."
Date: June 1977
Creator: Douglas, C. A. & Booker, R. L.
Partner: UNT Libraries Government Documents Department

Tables of Spectral-Line Intensities: Part 2 - Arranged by Wavelengths

Description: From Preface: "This new edition of the NBS Tables of Spectral-Line Intensities incorporates three improvements on the original edition of 1961. In the original edition only about 25 000 of the 39 000 lines in the tables had been classified. In the ensuing thirteen years, about 8500 more lines (chiefly rare-earths) have been classified and the new classifications are here incorporated."
Date: May 1975
Creator: Meggers, William F.; Corliss, Charles H. & Scribner, Bourdon F.
Partner: UNT Libraries Government Documents Department

Automatic Measurement of Network Parameters: A Survey

Description: Report issued by the Bureau of Standards over a survey conducted on measurement methods of network parameters. As stated in the introduction, "this paper is concerned with the development of automatic methods of measuring basically the magnitudes and phase differences, or the complex ratio of two sinusoidal voltages, and applications of this capability to determining complex reflection coefficients and transmission coefficients and group delay times of electrical networks" (p. 1). This report includes tables, and illustrations.
Date: June 1976
Creator: Beatty, Robert William
Partner: UNT Libraries Government Documents Department

Computers, Health Records, and Citizen Rights

Description: Report issued by the Bureau of Standards over studies on the benefits of computerized record-keeping. Medical records were chosen for the studies, and they also focus on patient privacy and rights. This report includes tables, and illustrations.
Date: December 1976
Creator: Westin, Alan F.; Baker, Michael A.; Annas, George J.; Silberberg, Richard; Broder, Jamie; Isbell, Florence et al.
Partner: UNT Libraries Government Documents Department

Selected Properties of Hydrogen (Engineering Design Data)

Description: Report issued by the Bureau of Standards over the thermophysical properties of hydrogen. Properties of hydrogen in varying states (gaseous, liquid, solid, etc.) are presented and discussed. This report includes tables, and illustrations.
Date: February 1981
Creator: Hord, J.; McCarty, Robert D. & Roder, H. M.
Partner: UNT Libraries Government Documents Department

An Institutional Plan for Developing National Standards: With Special Reference to Environment, Safety, and Health

Description: From Abstract: "This plan was commissioned to provide a framework for the development of all essential non-nuclear energy-related, environmental, safety, and health (ES&H) standards for the private sector to coincide with the commercialization of energy technologies."
Date: September 1979
Creator: Steiner, Bruce W.
Partner: UNT Libraries Government Documents Department

Measurement Assurance Program - A Case Study: Length Measurements. Part 1. Long Gage Blocks (5 in to 20 in)

Description: From Abstract and Introduction: "This paper is, in essence, a report on the extension of the techniques first suggested in NBS Monograph 103 "Realistic Uncertainties and the Mass Measurement Process" to the area of length measurement. This paper covers the progress to date on the long gage blocks (from 5 to 20 in the length). The purpose of this purpose is to verify the closure between the "old" process and the "new" process, and to describe the present "points of departure" upon which some of the current assigned length values are based."
Date: November 1975
Creator: Pontius, Paul E.
Partner: UNT Libraries Government Documents Department

Stress Corrosion Cracking Control Measures

Description: From Abstract: "This publication attempts to diminish the incidence of stress corrosion failures by assembling the available practical measures to avoid or minimize the problem and present these measures in a form comprehensible to those persons responsible for the design, fabrication, and maintenance of new structures."
Date: June 1977
Creator: Brown, B. F.
Partner: UNT Libraries Government Documents Department

Physical Properties Data for Rock Salt

Description: From Introduction Monograph Organization: "The Monograph is in six chapters covering the geological, mechanical, optical, thermal, radiation damage, electrical, magnetic, chemical, and physical properties of rock salt and pure NaCl. Each chapter has been written by a different author, or authors, consistent with his field of expertise."
Date: January 1981
Creator: Gevantman, L. H.; Lorenz, J.; Haas, J. L., Jr.; Clynne, M. A.; Schafer, C. M.; Potter, R. W., Jr. et al.
Partner: UNT Libraries Government Documents Department

Plane-Wave Scattering-Matrix Theory of Antennas and Antenna-Antenna Interactions

Description: From Abstract: "This monograph is distinguished by the use of plane-wave spectra for the representation of fields in space and by the consideration of antenna-antenna (antenna-scatterer) interactions at arbitrary separation distances." From Preface: "The primary objective of this monograph is to facilitate the critical acceptance and proper application of antenna and field measurement techniques deriving more or less directly from the plane-wave scattering matrix (PWSM) theory of antennas and antenna-antenna interactions. A second objective is to present some recent and some new theoretical results based on this theory."
Date: June 1981
Creator: Kerns, David M.
Partner: UNT Libraries Government Documents Department

The Nicrosil versus Nisil Thermocouple: Properties and Thermoelectric Reference Data

Description: From Abstract: "This monograph deals with the formulation and development of the new highly stable nickel-base thermocouple alloys Nicrosil (Ni-14.2Cr-1.4Si) and Nisil (Ni-4.4Si-0.1Mg) under the leadership of the Materials Research Laboratories (MRL) of the Australian Government of Defence, and their standardization by the National Bureau of Standards (NBS) of the U.S. Department of Commerce."
Date: April 1978
Creator: Burley, Noel A.; Powell, Robert L.; Burns, George W.; Scroger, Margaret G.; Burns, George W. & Scroger, Margaret G.
Partner: UNT Libraries Government Documents Department

Electromagnetic Boundary-Value Problems Based Upon a Modification of Residue Calculus and Function Theoretic Techniques

Description: From Introduction: "The first part of this monograph is concerned with the analysis of closed region wave-guide junction problems. This allows simplification of the techniques to be used since no branch cuts are involved in the spectral representation of the fields. However, the analysis can be extended to open region problems in a logical manner. This is the subject of the second part of this monograph."
Date: June 1979
Creator: Montgomerey, James Patrick & Chang, David C.
Partner: UNT Libraries Government Documents Department