Bulletin of the Bureau of Standards, Volumen1
U.S. Government Printing Office, 1904
Contains results of investigations, researches, etc., pertaining to scientific, technical and manufacturing interests of the country.
Comentarios de la gente - Escribir un comentario
No encontramos ningún comentario en los lugares habituales.
Otras ediciones - Ver todas
alternating amount ampere anode applied black body bridge Bureau calibration capacity cell cent charge circuit coil column comparison condenser connected considerable constant correction corresponding curve deposit determined distribution effect electric electrodes electromotive force employed energy equal equation error experiments expression four frequency galvanometer give given glass harmonic heated hence henry incandescent increase indicated inductance intensity lamp less light manner mean measurements mercury metallic meter method mirrors nearly object observed obtained ohms optical passed photometric Phys placed platinum position possible potential practical pressure produced pyrometer radiation readings relation relative resistance scale shown silver solution spectra spectrum speed standard surface Table taken temperature thermometers tion true tube units variations varying wave length weight wire
Página 61 - The unit of current shall be what is known as the international ampere, which is onetenth of the unit of current of the centimeter-gramsecond system of electro-magnetic units, and is the practical equivalent of the unvarying current, which, when passed through a solution of nitrate of silver in water in accordance with standard specifications, deposits silver at the rate of one thousand one hundred and eighteen millionths of a gram per second.
Página 46 - Ampere, which is one-tenth of the unit of current of the CGS system of electromagnetic units and which is represented sufficiently well for practical use by the unvarying current which, when passed through a solution of nitrate of silver in water, in accordance with a certain specification, deposits silver at the rate of 0.001118 of a gramme per second.
Página 61 - As a unit of resistance, the international ohm, which is based upon the ohm equal to 10" units of resistance of the CGS system of electromagnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice, 14.4521 grams in mass, of a constant cross-sectional area and of the length of 106.3 centimetres.
Página 372 - Custom-Houses, and for other purposes, to be delivered to the governor of each state in the Union, or such person as he may appoint, for the use of the states respectively, to the end that a uniform standard of weights and measures may be established throughout the United States.
Página 47 - The liquid should consist of a neutral solution of pure silver nitrate, containing about 15 parts by weight of the nitrate to 85 parts of water. The resistance of the voltameter changes somewhat as the current passes. To prevent these changes having too great an effect on the current, some resistance besides that of the voltameter should be inserted in the circuit.
Página 68 - ... distilled water with nearly twice its weight of crystals of pure zinc sulphate, and adding zinc oxide in the proportion of about 2 per cent, by weight of the zinc sulphate crystals to neutralise any free acid. The crystals should be dissolved with the aid of gentle heat, but the temperature to which the solution is raised should not exceed 30° C.
Página 74 - The International Ohm is the unit of resistance and is defined as the resistance offered to an unvarying current by a column of mercury at the temperature of melting ice, 14.4521 grams in mass, 106.300 cm.
Página 61 - ... international farad, which is the capacity of a condenser charged to a potential of one international volt by one international coulomb of electricity.
Página 61 - As a unit of electro-motive force, the international volt, " which is the electro-motive force that, steadily applied to a " conductor whose resistance is one international ohm, will '• produce a current of one international ampere...
Página 70 - In the following specification the term silver voltameter means the arrangement of apparatus by means of which an electric current is passed through a solution of nitrate of silver in water. The silver voltameter measures the total electrical quantity which has passed during the time of the experiment, and by noting this time the time average of the current, or if the current has been kept constant, the current itself, can be deduced.