ISSN:0034-6748    

DOI:10.1063/1.1751764

出版商:AIP    

年代:1934

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751765

出版商:AIP    

年代:1934

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751766

出版商:AIP    

年代:1934

数据来源: AIP

摘要:

Measurements of the electromotive force of standard cells made over periods of from seven to twenty years show that the electromotive force of the cells decreases at a rate which varies from cell to cell and which changes with the age of the cell. It seems further that a single cell may not be trusted unless it has been checked a short time previous to being used. These conclusions follow as the result of measurements where no attempt was made to keep the cells at a constant temperature.

ISSN:0034-6748    

DOI:10.1063/1.1751767

出版商:AIP    

年代:1934

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751768

出版商:AIP    

年代:1934

数据来源: AIP

摘要:

An instrument which may be used as a registering microphotometer, a direct reading densitometer and a comparator has been constructed. It utilizes a radiometer as the light‐sensitive device. Records are taken on 4 by 10 inch photographic plates, direct readings on a 50 cm scale, and intervals are read by means of a 10 inch comparator screw.

ISSN:0034-6748    

DOI:10.1063/1.1751769

出版商:AIP    

年代:1934

数据来源: AIP

摘要:

It is frequently desirable to generate very steady high voltage direct current from low voltage alternating current obtained from a source subject to violent fluctuation. An instrument is described which will maintain output voltage constant to less than one percent so long as the supply voltage remains in the range between 95 and 165 volts. The variation of output voltage with changes in applied load is 0.1 percent per milliampere. The pure direct current output may be varied easily and reproducibly between 100 and 2200 volts.

ISSN:0034-6748    

DOI:10.1063/1.1751770

出版商:AIP    

年代:1934

数据来源: AIP

摘要:

A device is described for making permeability‐tension tests on a ferromagnetic material in the form of a tape bent into a triangle. This form has the advantage over the usual straight one in that it forms a closed magnetic circuit to which tension can be easily applied. The magnetic measurements at low magnetizing forces are made by means of the Kelsall permeameter which obviates the necessity of winding a large number of turns of wire around the specimen. The magnetic measurements at high magnetizing forces are made in the customary manner with a ballistic galvanometer. The method is illustrated by tests on perminvar specimens.

ISSN:0034-6748    

DOI:10.1063/1.1751771

出版商:AIP    

年代:1934

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751772

出版商:AIP    

年代:1934

数据来源: AIP

摘要:

In an article under the above title inThe Review of Scientific Instruments, Volume 2, page 611, October, 1931, the unit of field strength used throughout was lines per square inch, not gauss as originally reported.

ISSN:0034-6748    

DOI:10.1063/1.1751773

出版商:AIP    

年代:1934

数据来源: AIP