DOI:10.1049/jiee-1.1927.0092

出版商:IEE    

年代:1927

数据来源: IET

摘要:

In Part 1, possible methods of calibrating a Rayleigh disc are discussed, and details are given of a comparison between two of these, namely, by means of low-frequency alternating air currents and by calculation based on the theoretical formula. In consequence of agreement found between these, the latter has been adopted as the most convenient practical method of calibration.In Part 2, comparisons are made between Rayleigh discs of different sizes and compositions, both in spherical sound waves and in a closed resonating tube. The influence of internal resonances of mica discs on velocity measurement is investigated.In Part 3, comment is made on practical considerations affecting acoustic measurements by means of a Rayleigh disc.

DOI:10.1049/jiee-1.1927.0097

出版商:IEE    

年代:1927

数据来源: IET

摘要:

The paper presents details of the equipment of a laboratory devoted to the problems of broadcast reception. Among the special equipment developed are:—Galvanometer lamps; a distribution system for battery d.c. supply; an elaborate valve tester; an audio source; a standard valve voltmeter ; a combined a.c. and d.c. bridge; and interchangeable high-frequency resistors.Special methods are described in connection with insulation tests of condensers ; correction of wattmeter errors; measurement of amplification; self-capacity of coils and their high-frequency resistance ; and keeping records.

DOI:10.1049/jiee-1.1927.0098

出版商:IEE    

年代:1927

数据来源: IET

摘要:

Formulæ for calculating the eddy-current loss in the bonded sheaths of single-conductor cables have been published in theI.E.E. Journal.These contain a term log [(1−K)/K] instead of the usual term log (1/K) used by most authors in formulae for this purpose, namely those published in theElectric Journal. These two terms are caused by using different limits in integrating the conductor flux, thereby producing quite a difference in the results obtained by the two methods.The present author has carried out an investigation by working out a practical example, using an independent method, with a view to determining which formula is correct. The results of this investigation show that for close or practical spacing the formulae published in theI.E.E. Journalgive a result too low and also that the term log[(1−K)/K] should be changed to log (1/K)

DOI:10.1049/jiee-1.1927.0100

出版商:IEE    

年代:1927

数据来源: IET

DOI:10.1049/jiee-1.1927.0101

出版商:IEE    

年代:1927

数据来源: IET