ISSN:0034-6748    

DOI:10.1063/1.1752373

出版商:AIP    

年代:1938

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752374

出版商:AIP    

年代:1938

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752375

出版商:AIP    

年代:1938

数据来源: AIP

摘要:

An air‐insulated direct‐current electrostatic generator of the Van de Graaff type, characterized by simplicity and low cost and suitable for a wide variety of research applications, is described. The generator, which employs re‐entrant terminals, is capable of 500 kv and produces a short‐circuit current of about 200 microamperes with a single 10″ belt. The manner in which the unit can be extended to higher voltages and currents is indicated, as well as the effect of operation in the presence of CCl4and CCl2F2vapors. The operating principles, design considerations, theory of multiple belts, effect of humidity, problem of surge elimination, and cost are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1752376

出版商:AIP    

年代:1938

数据来源: AIP

摘要:

This spectrograph records upon sheets of photographic paper 20×30 inches in size, spectra lying in the range between 18&mgr; and 200&mgr;. Of this range, 9&mgr; may be spread over a single record, or as much as 100&mgr; may be covered, depending upon the gratings and the adjustments used. The spectrograph is a vacuum instrument of high resolving power, being capable of separating sharp lines somewhat closer than 0.5 cm−1apart. Detailed drawings of its construction together with several records are shown and described. The recorded galvanometer deflections are usually adjusted to lie between 100 and 300 mm.

ISSN:0034-6748    

DOI:10.1063/1.1752377

出版商:AIP    

年代:1938

数据来源: AIP

摘要:

A method of spinning tubular rotors to high speeds in a vacuum is described. The rotors are spun by air‐supported, air‐driven turbines situated below the vacuum chamber. The maximum rotational speed attainable is set only by the bursting strength of the tubular rotor. The material to be centrifuged enters the spinning tube at the top at a continuous rate and is collected in light and heavy fractions at the bottom. The apparatus has been used for centrifuging materials in gaseous, vapor and liquid states.

ISSN:0034-6748    

DOI:10.1063/1.1752378

出版商:AIP    

年代:1938

数据来源: AIP

摘要:

A radiometer‐type vacuum gauge is described, which is rugged and simple to construct, which can be calibrated from the dimensions of the gauge, and for which the temperature of the moving system does not enter. The gauge, when constructed entirely of metal has a range from 2 dynes per square centimeter to 0.01 dyne per square centimeter. If constructed of glass, the lower limit can be extended to 0.001 dyne per square centimeter or better.

ISSN:0034-6748    

DOI:10.1063/1.1752379

出版商:AIP    

年代:1938

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752380

出版商:AIP    

年代:1938

数据来源: AIP

摘要:

The problem of stopping a moving light‐beam on the edge of a phototube without any tendency to oscillate or ``hunt,'' and with speed and precision has been solved by a new method and a recording potentiometer is rapidly and accurately balanced. By (1) artificially canceling the generated back e.m.f. of the moving galvanometer thus advancing its return movement from a deflected position, and (2) delaying the grid potential change of a triode amplifier in the photoelectric circuit, galvanometer lag is counteracted and the potentiometer is balanced with an accuracy of a few hundredths of a percent of the range. The total power input to the instrument is about 35 watts and the contact carriage speed is made as high as 10″ in 20 seconds.1The fundamentals of the complete instrument are discussed and equations describing the galvanometer movement are included.

ISSN:0034-6748    

DOI:10.1063/1.1752381

出版商:AIP    

年代:1938

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752382

出版商:AIP    

年代:1938

数据来源: AIP