摘要:

The article deals with a photoelectric method of measuring the intensity of a beam of light at any point of its cross‐sectional area. The application of this method led to the production of a light beam the intensity of which over an area 30 cm×30 cm varied by less than one‐third percent.

ISSN:0034-6748    

DOI:10.1063/1.1749011

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

The fundamental principles of the interferometer, particularly the liquid supersonic interferometer of Hubbard and Loomis, are incorporated in an instrument in which the liquid under examination may be put under pressures up to about 10,000 lb./sq. in. The instrument and the pressure device are built into a block of special cast steel 8×5×4½ inches. The results given are preliminary and merely show the performance and precision of the instrument. A curve is given showing the change of velocity of a high frequency acoustic wave of 195 kc from 1143 meters per second at atmospheric pressure to 1233 meters per second at a pressure of 3105 lb./sq. in. in carbon disulphide at room temperature. (The room temperature varied at different readings from 22.25°C to 25.41°C.)

ISSN:0034-6748    

DOI:10.1063/1.1749012

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749013

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749014

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749015

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749017

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

To compare results of incandescent lamp tests expressed in terms of the spread (maximum difference) observed in sets of various numbers of lamps, factors were required to convert these results to a comparable basis. The average deviation of a single observation was chosen as the basis of comparison. To avoid the necessity of computing the probable error, a table of the probability integral for the argument &tgr; = &pgr;½tis given. Assuming a Gaussian distribution of errors, the factors have been tabulated for numbers of observations up to 100,000. They are given approximately by the semi‐empirical formulas: spread/ave.deviation=f(n)=2&pgr;12ta≐(50296−20086/(0045+lg n))(lg n)12≐507 (lg n)12−1075. While the average deviation so computed is less precise than that computed from the sum of the residuals, ora fortioriof their squares, the difference seldom exceeds the uncertainty of the more refined measures. Conventions are suggested for the retention of figures and for the statement of measures of deviation. The labor of computing the average deviation from the spread is so slight that an expression of the internal consistency ofallresults of physical measurements may reasonably be required.

ISSN:0034-6748    

DOI:10.1063/1.1749030

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749042

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749045

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749046

出版商:AIP    

年代:1933

数据来源: AIP