Skip to main content

Bulletin of the Bureau of Standards

Results of research in science and technology at the National Bureau of Standards were reported in Scientific Papers. The first 14 volumes of the Scientific Papers were issued as the Bulletin of the Bureau of Standards. These volumes date from 1904 to 1919. The separate papers were called Reprints.



rss RSS

359
RESULTS


Show sorted alphabetically

Show sorted alphabetically

SHOW DETAILS
up-solid down-solid
Prior Page
eye
Title
Date Published
Creator
Bulletin of the Bureau of Standards
texts

eye 343

favorite 0

comment 0

This apparatus is H-shaped with test coils ST spanning the free ends of the H and a magnetising coil M wound on the cross-piece. D and D' are also test coils. SDD'T have the same number of turns and are connected in series and in such a manner that the integrated e.m.f.'s induced in S and D' when a magnetising current is reversed in M are in the same direction but in opposition to those simultaneously induced in D and T. The permeameter is initially adjusted so that when the coils S and T...
Topics: magnetism, measurements and use of instruments/ B8000 Power systems and applications
Bulletin of the Bureau of Standards
texts

eye 263

favorite 0

comment 0

The modern form of the Koepsel permeameter is an instrument very similar in shape and size to a moving-coil ammeter. It gives direct readings of the magnetising force and the flux density. The moving part is a coil through which a constant current flows, and the deflection of this coil is used to measure the magnetic field. The magnetic circuit consists of a yoke with its ends joined by the test-piece. The middle of the yoke has a circular gap in which swings the test-coil for the measurement...
Topics: magnetism, measurements and use of instruments/ B8000 Power systems and applications
Bulletin of the Bureau of Standards
texts

eye 307

favorite 0

comment 0

measurements and use of instruments; Electrical instruments and techniques
Topic: USA
Bulletin of the Bureau of Standards
texts

eye 260

favorite 0

comment 0

The device of holding the instrument with the moving element horizontal and sliding a weight along the needle until the desired deflection is obtained with the needle horizontal is not suitable for such a purpose or for such instruments as watt-hour meters. The method here described is suitable for such a purpose or for the measurements of any small horizontal force. A bob with vertical pointer attached is suspended vertically by a silk fibre from a support so that it can move just over a...
Topic: apparatus and instruments/ B8000 Power systems and applications
The present paper gives data relating principally to the determination of the mathematical form of the isothermal spectral curve of a black body, and to the computation of the numerical value of the constants relating thereto, for the temperature-range between 450 degrees and 1525 degrees C. The paper also contains data on various subsidiary problems such as (i) the variations of the reflecting power of silver with angle of incidence and with wave-length, (ii) the variation of the reflecting...
Topics: measurements and use of instruments, rays and radiation, Heat flow, thermal and thermodynamic...
Bulletin of the Bureau of Standards
texts

eye 215

favorite 0

comment 0

Topic: table of contents
Bulletin of the Bureau of Standards
by Austin, L.W.
texts

eye 142

favorite 0

comment 0

Bulletin of the Bureau of Standards
by Vinal, George W.
texts

eye 215

favorite 0

comment 0

The relation between the energy of oscillation in two coupled circuits and the coefficient of coupling is investigated. The primary aircraft is excited by means of a vibrator worked by an electromagnet, and this circuit excites the two coupled circuits under observation. The arrangement is taken as representing a sender and a receiving circuit with a detector circuit coupled to it. It is the energy relations in the last two which are studied. A Pt-Te thermo-couple or a zincite-chalcopyrite...
Topics: radiotelegraphy, oscillations and waves (electric)/ B6210F Telegraphy
Bulletin of the Bureau of Standards
by Brooks, H.B.
texts

eye 915

favorite 0

comment 0

A method of testing instrument transformers by means of ordinary commercial testing instruments is described. It has to be remembered that from the practical point of view we need only take account of these errors in ratio or phase angle which produce a visible error in the reading of the indicating wattmeter. A wattmeter is taken and used in such a way that differences in ratio or phase angle of the transformer being tested and a standard transformer may be most readily detected. The method is...
Topics: transformers, rotary converters and boosters, measurements and use of instruments/ B8300 Power...
The densities of copper sulphate-sulphuric acid solutions of varying concentrations have been determined at 25 degrees and 40 degrees . The concentrations of the solutions varied from 50 gm, to 300 gm. of total solute per kg. of solution. Within the range studied the density of the solutions is approximately a linear function of the concentration. The densities of solutions of equal-weight (not equivalent) concentrations of copper sulphate (CuSO/sub 4/5H/sub 2/O) and of sulphuric acid are...
Topics: solution and solubility, Physical chemistry
Bulletin of the Bureau of Standards
by Bingham, Eugene C.; Jackson, Richard F.
texts

eye 788

favorite 1

comment 0

As a result of the investigation of various liquids for use as standards in the calibration of viscometers of several forms, it is concluded that mixtures of 20, 40, and 60% ethyl alcohol in water (by weight), and solutions of 20, 40, and 60% of surcrose are the most suitable. Tabulated values of the viscosities and fluidities of these liquids from 0 degrees to 100 degrees C. at intervals of 10 deg. C. are given. From the curves of fluidities given it is considered that, owing to their simple...
Topics: viscosity, General Physics
Bulletin of the Bureau of Standards
by Hulett, G.A.; Vinal, G.W.
texts

eye 169

favorite 0

comment 0

A study of the various methods of measuring the time-constants of four-terminal resistance standards, which are classified into two main types, viz. (1) those in which the working material is formed into a /b closed/ circuit of as little self-inductance as possible, and the potential leads kept free from all inductive effects, and (2) those in which the potential leads are placed as close as possible to this working resistance so that the mutual inductance of the lead and the resistance is...
Topics: inductance, Condensed matter, electronic structure, electrical, magnetic, and optical properties
Bulletin of the Bureau of Standards
texts

eye 607

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 381

favorite 0

comment 0

The authors suggest the use of the name "inductor" for apparatus used to introduce "inductance" into a circuit, as well as "resistor" for apparatus possessing the property of "resistance." The paper describes the method of evolution and construction of an inductor having a range of variation of about 1 millihenry and a current-carrying capacity of about 5 amps. The form of apparatus considered to be most suitable is that consisting of two circular plates...
Topics: apparatus and instruments, Condensed matter, electronic structure, electrical, magnetic, and...
Bulletin of the Bureau of Standards
by Coblentz, W.W.
texts

eye 205

favorite 0

comment 0

Greater sensitiveness is obtained by placing the whole in a vacuum.
Topic: apparatus and instruments/ B7500 Medical physics and biomedical engineering
Bulletin of the Bureau of Standards
by Lloyd, M.G.; Agnew, P.G.
texts

eye 297

favorite 0

comment 0

measurements and use of instruments;Medical physics and biomedical engineering
Topic: USA
The method used consists in heating a small quantity of the metal whose melting-point is to be observed on a platinum strip through which a current is passed. This is surrounded by a blackened brass tube with a mica window, and the sample is simultaneously watched by two observers through a microscope and an optical pyrometer. In the calibration of the optical pyrometer 1,753 degrees was taken as the Pt melting-point. The correction for absorption and reflection by the mica is about 15 degrees...
Topics: freezing, melting and boiling points, measurements and use of instruments, thermometry, pyrometry...
Particulars have been given of some tests on tubes containing helium with a view to their being used as standards of light. It was then found that small differences in thickness in the bore of the capillary tubes used introduced errors and more uniform tubes, which were also fairly free from striations, have since been obtained. Details of the photometric tests to which these tubes were subjected are given. The mean deviation in candle-power per cm. length of tube is found to be 1.15 per cent.,...
Topic: photometry
Topics: alternating-current research, inductance, Electricity and magnetism, fields and charged particles
Bulletin of the Bureau of Standards
by Burgess, G.K.
texts

eye 159

favorite 1

comment 0

Bulletin of the Bureau of Standards
by Osborne, Nathan S.; Van Dusen, Milton S.
texts

eye 925

favorite 0

comment 0

Writing Planck's equation for the intensity, J, of radiation of wave-length lambda from a black body at the absolute temperature thetas in the form, J=c/sub 1/ lambda /sup -5/(c'/sup 2/ lambda thetas /-1)/sup -1/. the authors point out a way of computing the constant c/sub 3/ by an extension of Paschen's method of equal ordinates. In an illustrative energy-curve for thetas = 1442 degrees abs., the constant /b e//sub 2/ is taken as 14,500; this gives a maximum ordinate at lambda /sub m/ = 2mu.
Topic: thermodynamics
In the first part of the paper measurements are given of the radiation from the Hefner lamp and from a standard sperm candle relative to that of a black body. The radiation from these standard sources is given in absolute values on the assumption that the radiation constant is 5.7*10/sup -12/ watt cm./sup 2/ deg./sup -4/, which is practically the mean value of the best present-day determinations. The data are considered to be useful for rough calibrations of radiometers in absolute measure. For...
Topics: rays and radiation, thermometry, pyrometry and calorimetry, Heat flow, thermal and thermodynamic...
Bulletin of the Bureau of Standards
texts

eye 440

favorite 0

comment 0

The investigations carried out up to the present time on the equilibrium diagram of the iron-carbon system cannot b6 regarded as exhaustive, because in no case have the investigators worked with pure materials. On this account the authors have prepared a series of alloys containing 0.08 to 3.27% of carbon to serve as the basis for an accurate study of the thermal equilibrium of the Fe-C system. Pure iron has been made by the electrolysis of American ingot iron, and a detailed study has been...
Topics: metallography and properties and treatment of metals and alloys, Electrochemistry and...
Bulletin of the Bureau of Standards
by Dellinger, J.H.
texts

eye 203

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 334

favorite 0

comment 0

An experimental investigation of the conditions for the production of oscillations by means of an arc placed (1) in air, (2) in hydrogen, (3) in steam, (4) in compressed air. In air the arc was formed (240-volt circuit) with electrodes of solid carbon, cored carbon copper, graphite, and copper as anode with carbon kathode. In all cases oscillations of frequency 100,000 per sec. were obtained, thus confirming Salomonson's results, but only in the case of graphite electrodes were steady...
Topics: radiotelegraphy, discharges (electric), oscillations and waves (electric)/ B6210 Telecommunication...
Bulletin of the Bureau of Standards
by Dickinson, H.C.; Osborne, N.S.
texts

eye 182

favorite 0

comment 0

Making use of the wedge method described by Mendenhall, the author has determined the monochromatic emissivity of nickel oxide at various temperatures within the range 700 degrees to 1300 degrees C. By means of a spectro-photometer of the Lummer-Brodhun type, observations were made for the wave-lengths 0.5mu, 0.6mu, and 0.7mu respectively. The wedge-shaped nickel strip was heated in a specially constructed furnace, and determinations of the relative intensities of the light emitted by the...
Topics: rays and radiation, thermometry, pyrometry and calorimetry, Heat flow, thermal and thermodynamic...
Bulletin of the Bureau of Standards
texts

eye 189

favorite 0

comment 0

The two types of electronic impact previously found in mercury vapour are also found in cadmium vapour. The sudden decrease in current through the retarding field at an effective potential of 3.88 volts indicates a loss in energy of electrons having this critical velocity on impact with a cadmium atom. The fact that there is no corresponding increase in the total current at 3.88 volts shows there is no appreciable ionisation at this potential. When the velocity of the electrons corresponds to...
Topic: spectra
Bulletin of the Bureau of Standards
texts

eye 214

favorite 0

comment 0

A more comprehensive account of the device described in.
Topic: apparatus and instruments
Bulletin of the Bureau of Standards
texts

eye 253

favorite 1

comment 0

For the first time, it is believed, a pyrheliometer has been calibrated by two methods, the usual electrical method and a radiometric method. In the radiometric method a known quantity of radiation from a black body was allowed to fall upon the pyrheliometer receiver in exactly the same manner as when employed for solar measurements. The calibrations by the two methods agreed within limits of experimental error, if the Stefan-Boltzmann constant were chosen as sigma = 5.7*10/sup 12/ watts...
Topics: meteorology, General Physics
In magnetic measurements made at the Bureau of Standards it has been found that the heating effect of the current, employed to produce fields of 100 to 300 gauss, changes appreciably the value of the induction for a given field. The usual practice, when an accuracy of 1 % is desired, has been to immerse the coil in an oil bath maintained at a constant temperature of 25 degrees . The object of the present investigation is to determine the magnitude of the temperature effect and to see whether it...
Topics: magnetism, Magnetic properties and materials A4100 Electricity and magnetism, fields and charged...
It is shown that while the transformation ratio of current transformers usually decreases with increasing current, it may increase in individual cases or even attain a maximum. This ratio and the phase-angle at various loads can be accurately computed from the magnetic data of the core. The slope of the ratio curve can in general be qualitatively predicted from the value of the Steinmetz coefficient. But the iron losses, especially at low flux densities, cannot be accurately- represented by a...
Topic: transformers, rotary converters and boosters/ B8300 Power apparatus and electric machines
In connection with the proposed systematisation of heterochromatic measurements the work described was planned to show the difference to be expected between individuals and to include readings by a large number of observers so as to establish average values for various measurements involving colour differences. The paper is divided into sections dealing with: Measurements on the Ives-Kingsbury solutions for selection of observers; measurements on blue glasses; other measurements by selected...
Topics: measurements and use of instruments, photometry
Bulletin of the Bureau of Standards
by Buckingham, E.
texts

eye 767

favorite 0

comment 0

Bulletin of the Bureau of Standards
by Ives, Herbert E.
texts

eye 249

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 191

favorite 0

comment 0

Topic: table of contents
Bulletin of the Bureau of Standards
texts

eye 166

favorite 0

comment 0

Topic: table of contents
Bulletin of the Bureau of Standards
texts

eye 163

favorite 0

comment 0

Topic: Table of contents
Bulletin of the Bureau of Standards
texts

eye 201

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 201

favorite 0

comment 0

In the case of solids investigated which have banded emission spectra, the distribution of intensities among the emission bands varies with rise in temperature. The distribution of energy seems to follow a law similar to that of a complete radiator in which the wave-length of max. intensity decreases with rise in temperature. Curves are given showing the relation between the emissivity and the wave-length for various minerals. Talc which was rendered incandescent on a heater tube, as in the...
Topics: rays and radiation, spectra
Bulletin of the Bureau of Standards
by Coblentz, W.W.
texts

eye 237

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 166

favorite 0

comment 0

Bulletin of the Bureau of Standards
by Coblentz, W.W.
texts

eye 256

favorite 0

comment 0

Topics: light reflection, thermoelectricity, Condensed matter, electronic structure, electrical, magnetic,...
Bulletin of the Bureau of Standards
texts

eye 530

favorite 0

comment 0

The Arsem vacuum furnace previously used was slightly modified, and arrangements were made to sweep out the smoke from the heated oxides which affects the optical pyrometer readings. The materials as a rule are charged into the ring space between an outer and an inner tube; some gas (hydrogen, nitrogen, etc.), is passed down the inner tube, into which the pyrometer is sighted. The tubes are made of graphite or of tungsten, the latter being moulded in graphite. The pyrometer lamps were...
Topics: freezing, melting and boiling points, materials properties, Heat flow, thermal and thermodynamic...
Tissot has already pointed out the advantages of high spark-frequency when thermal detectors are employed. The author demonstrates that a high spark-frequency is also advantageous from the point of view of the telephone receiver. Rayleigh's and Wien's results are quoted as showing the rapid increase of sensitiveness with the frequency, and a curve of volt-sensitiveness is given for a pair of 800-ohm Schmidt-Wilckes head telephones of the type used for radio-telegraphic work. The change in...
Topics: radiotelegraphy, acoustics, Telephony B6210F Telegraphy
Bulletin of the Bureau of Standards
texts

eye 170

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 246

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 242

favorite 0

comment 0

Topic: index
Bulletin of the Bureau of Standards
texts

eye 208

favorite 0

comment 0

Topic: index
An examination is made of the theory of the Matthews and the Russell-Leonard photometers in connection with the design of instruments of this type for the Bureau of Standards. It is pointed out that the assumption by Matthews of a sphere given by the equation I = I' sin thetas as a candle-power surface in order to check the error made by taking a limited number (11 pairs) of mirrors is inadmissible. In this case a single mirror pair would give the true m.s.c.p. By considering various...
Topics: photometry, lamps and lighting, Optics
Bulletin of the Bureau of Standards
by Nutting, P.G.
texts

eye 134

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 493

favorite 0

comment 0

In a previous paper Middlekauff and Skogland derived characteristic equations for the performance of tungsten lamps in terms of the applied voltage. These results are now applied to the construction of a chart by means of which, if the watts per c.p. are known at any voltage, the c.p. and the watts per c.p, at any other voltage may be read off directly. A chart is given which has a range of voltage of 94 to 166 volts, and a range of watts per c.p. of 0.70 to 2.05. Tables of figures drawn up by...
Topic: lamps and lighting/ B8530B Light sources
Bulletin of the Bureau of Standards
by Nutting, P.G.
texts

eye 250

favorite 0

comment 0

Bulletin of the Bureau of Standards
by Waidner, C.W.; Burgess, G.K.
texts

eye 190

favorite 0

comment 0

An expression for the ratios of the reflected and transmitted waves to the incoming wave at a transition point is developed in a simple manner. The paper cannot be fittingly abstracted.
Topic: oscillations and waves (electric)/ B7500 Medical physics and biomedical engineering
Bulletin of the Bureau of Standards
texts

eye 221

favorite 0

comment 0

Topic: cables, conductors and wiring/ B8000 Power systems and applications
Bulletin of the Bureau of Standards
by Rosa, E.B.
texts

eye 233

favorite 0

comment 0

Except for a few preliminary remarks on photometric units, this paper is mainly devoted to a series of calculations of formulae enabling the illumination at a given distance from sources of various dimensions, such as spheres, discs, infinite planes,
Topics: lamps and lighting, photometry/ B8530 Lighting technology
The object of the investigation was the determination of the spectral visibility curve of the average eye, 130 subjects being tested, of whom 7 were known to be colour-blind. The distribution of energy in the source of light used, a cylindrical acetylene flame, was determined with great care, and visibility curves extending from 0.46 mu to 0.74 mu were obtained by using a ficker photometer. Observers experienced little difficulty in making settings with this instrument, but wide variations were...
Topic: vision
Bulletin of the Bureau of Standards
texts

eye 157

favorite 0

comment 0

Bulletin of the Bureau of Standards
texts

eye 309

favorite 0

comment 0

This paper gives the theory and description of some two-circuit electrodynamometers, with standarised shunts, built at the Bureau of Standards and used for measuring alternating currents. When the instruments are compensated for the resultant inductance and capacity of the moving-coil circuit, they have the same constant for alternating current as for direct, and may therefore be calibrated by direct currents. The author first shows that in an instrument in which the self-inductance of the...
Topics: alternating-current research, apparatus and instruments, measurements and use of instruments,...
Bulletin of the Bureau of Standards
texts

eye 608

favorite 0

comment 0

The freezing-point of mercury was determined by means of resistance thermometers calibrated at 0 degrees , 100 degrees , and the sulphur boiling-point (444.6 degrees at normal pressure). Various precautions were observed to avoid errors due to impurities in the mercury, conduction along the leads, and the heating effect on the thermometers of the measuring current. The mean value - 38.873 degrees C. was obtained for the freezing-point, the max. deviation of any determination from the mean being...
Topics: freezing, melting and boiling points, Heat flow, thermal and thermodynamic processes
Bulletin of the Bureau of Standards
texts

eye 313

favorite 0

comment 0

This paper gives quantitative data on the absorption, reflection, and dispersion of quartz, extending from the ultra-violet to 3mu in the infra-red. The data may be used in determining spectral energy curves. Quartz is practically transparent from the ultra-violet to 1.8mu. It begins to absorb strongly beyond 1.8mu, and tabulated data are given for eliminating the effect of this absorption in a quartz prism. The results show that (within the errors of observation) in unpolarised light, the...
Topics: absorption (light and heat), light reflection
Bulletin of the Bureau of Standards
texts

eye 205

favorite 0

comment 0

The author suggests that there is a need for some method of estimating the resemblance of artificial illuminants to daylight, /b i.e./, of determining their "daylight efficiency." Assuming that, by the extraction of certain qualities of light in an illuminant its colour could be brought to resemble that of daylight very closely, the daylight efficiency of a source might be expressed in the form (intensity of available white light)/(total intensity of source). The author suggests two...
Topics: photometry, lamps and lighting
Bulletin of the Bureau of Standards
by Osborne, Nathan S.; Van Dusen, Milton S.
texts

eye 401

favorite 0

comment 0