ISSN:0034-6748    

DOI:10.1063/1.1752311

出版商:AIP    

年代:1937

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752312

出版商:AIP    

年代:1937

数据来源: AIP

摘要:

A curve tracer is described which enables the relationship between two, three, or four variables to be observed and recorded. An optical arrangement is made to project an image of an L‐shaped aperture onto photographic paper for recording, onto a mat screen for observation, or onto a larger screen or blackboard for demonstration purposes. By means of the surface mirrors attached to two measuring instruments, the image of the aperture may be moved to any point on the screen depending on the deflection of the instruments. By means of the two light shutters attached to two other instruments the lengths of the vertical and horizontal arms of the L aperture are determined by the instrument deflections. Thus the apparatus provides a two‐coordinate system (the image of the L‐shaped aperture) moving within a second two‐coordinate system (the screen). Thus the value of two, three, or four variables can be seen at a glance, and their interrelations watched while one or more of the variables is altered. The scale on any axis may be altered by the adjustment of a continuously wound shunt. Any small variation that may be of special interest may thus be readily magnified. Full scale deflection for each component is obtained over a range from 20 mv to 2000 v or 2 ma to 2 amp. The maximum size of the photographic record is 13×18 cm. The apparatus is not concerned with rapidly varying phenomena, except insofar as these may be registered as the steady deflection of a measuring instrument. The application of the instrument is described in relation to the characteristics of a split‐anode magnetron.

ISSN:0034-6748    

DOI:10.1063/1.1752313

出版商:AIP    

年代:1937

数据来源: AIP

摘要:

A compensating circuit comprising two blocking‐layer photoelectric cells in a parallel connection with a galvanometer and potentiometer‐rheostat is described. Analysis of the circuit shows that a uniform scale attached to the potentiometer‐rheostat may be used to indicate transmission (or reflectance) of light by a sample if the resistance of the potentiometer and the series internal resistances of the photoelectric cells are small in comparison with the parallel internal resistances of the photoelectric cells. The performance of the circuit under different conditions was tested by means of wire screens of known transmission. With moderate illumination on the photoelectric cells and using a 50 ohm potentiometer‐rheostat carrying a scale graduated from 0 to 100, errors in indicating transmission are believed to be not greater than ±0.1 on this scale.

ISSN:0034-6748    

DOI:10.1063/1.1752314

出版商:AIP    

年代:1937

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752315

出版商:AIP    

年代:1937

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752316

出版商:AIP    

年代:1937

数据来源: AIP

摘要:

This report describes in detail with photographs and cross‐sectional views an x‐ray tube with a gyrating water‐cooled target which the authors have operated continuously for periods of hours at 287,000 volts and 105 milliamperes. The theoretical predictions of DuMond, Watson and Hicks as to the ratio of safe load in moving and fixed targets seems to be roughly fulfilled by these results. The computed power output in the form of x‐rays alone is some 3/4 kilowatt. The report further describes in detail the power supply equipment consisting of a synchronous motor driven 40 kw motor generator set giving 150 cycle current both half‐waves of which, after transformation to high voltage, are rectified by two thermionic valves (filament emission 2 amperes maximum) of our own design and construction here fully described. The powerful electrical filter system to reduce the ripple to a low value and some technical problems arising from the large power rating of the equipment as well as the facilities now almost completed for stabilizing and measuring precisely the high voltage supplied to the x‐ray tube are discussed. At the outset a brief indication of the program of research work projected for this set is given.

ISSN:0034-6748    

DOI:10.1063/1.1752317

出版商:AIP    

年代:1937

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752318

出版商:AIP    

年代:1937

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752319

出版商:AIP    

年代:1937

数据来源: AIP