Mercury barometers and manometers

Abstract

The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950* These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, ana structures; advisory services to government agencies on scientific and technical problems; in vention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required* The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. PublicationsThe results of the Bureau's work take the form of either ^ctual equipment and devices or pub lished papers. These papers appear either in the Bureau's own series of publications or in the journals of professional and scientific societies. The Bureau itself publishes three periodicals available from the Government Printing Office: The Journal of Research, published in four separate sections, presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre liminary reports on work in progressJ and Basic Radio Propagation Predictions provides data for determining the best frequencies to use for radio communications throughout the world. ForewordPreparation of this Monograph on mercury barometers and manometers was undertaken to fill the need of manufacturers and users for information which is now scattered through the literature and in some cases unpublished. This information is primarily on the sources of error and methods for their correction. Moderately extensive tables of corrections for temperature, gravity, capillarity, and other errors are included, mainly for application to portable instruments. The various types of instruments are defined and design features affecting the accuracy discussed in some detail.The preparation of this monograph is part of the work on pressure stand ards now in progress in the Mechanics Division, B. L. Wilson, Chief, under the direct supervision of E. C. Lloyd, Chief of the Mechanical Instruments Section.A. V. ASTIN, Director. in The various designs of mercury barometers and manometers are briefly described, with a more extended discussion of the various design elements which may affect the achievable accuracy. Sources of error in measuring pressures are described in considerable detail, par ticularly for portable instruments, including scale...

An apparatus for direct fugacity measurements on mixtures containing hydrogen

“…The vent valve, C, allows the sample pressure to be dropped to ambient before injection. The ambient pressure is measured using a fixed cistern mercury barometer, with the appropriate corrections being applied to the readings [30]. provided by a proportional controller which responds to a thermistor sensor.…”

Reference tables for low-temperature thermocouples

“…2 Compares front and back ends of a single roll-30 to 150 meters. 3 Widely separated lengths of wires from different spools. (a) Short-range inhomogeneity probe, (b) Mediumrange, long-range, and inter-lot homogeneity probe, (c) Differential thermocouple probe.…”

“…No values were available for the He to N2 range. 3 Interim values are from low temperature thermocouple tables by R. L. Powell, et al, of the Cryogenics Division, National Bureau of Standards, Boulder, Colorado, distributed Summer, 1965, as an informal report.…”

Equilibrium decomposition pressures of the compounds Cs2ZrCl6 and Cs2HfCl6 and X-ray identification of Na2HfCl6, K2HfCl6, and Cs2HfCl6

“…Tressures were measured in m m Hg, and corrections were made for mercury expansion and for gravity effects (12,13) to convert to standard conditions, i.e. at 273.15 K and an acceleration of free fill1 of 9.80665 m/s'.…”