ISSN:0034-6748    

DOI:10.1063/1.1751953

出版商:AIP    

年代:1935

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751954

出版商:AIP    

年代:1935

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751955

出版商:AIP    

年代:1935

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751956

出版商:AIP    

年代:1935

数据来源: AIP

摘要:

The peculiarities of design in this pump are, the use of streamlines in regions of high pressure and the introduction of small angle conical surfaces for baffles in the regions of lower pressures. The conical baffles are particularly effective in preventing oil vapor from entering the chamber to be evacuated and at the same time in offering a minimum of impedance to the flow of gas through the pump. A three‐inch pump with this design and operating on a Western mineral oil especially prepared for it in this laboratory has shown a pumping speed in excess of 50 liters per second at a pressure of 1.0×10−4mm.

ISSN:0034-6748    

DOI:10.1063/1.1751957

出版商:AIP    

年代:1935

数据来源: AIP

摘要:

This treatise is an exposition of the measurement of high frequency sound by means of an originally designed and constructed apparatus, together with results obtained and the interpretation thereof. The apparatus consists of a high precision, supersonic, sending and receiving system of a triple‐quartz‐plate type. Two of the piezo‐quartz plates used act as supersonic transducers to transform electromagnetic energy into gas pressure waves and to retransform them. The third plate, of the same frequency, controls the oscillations of an external vacuum tube circuit, the output of which drives and controls the frequency of the first transducer plate in the gas chamber, within extremely narrow limits. An original interference method is used to eliminate troublesome standing waves along the supersonic path. The signal, amplified for observation, is the vector sum of the electromagnetic wave impressed on the receiver by the retransformed energy and a controlled direct pick‐up through the capacity coupling of the high voltage leads to the gas chamber. The amplifier consists of two stages of radiofrequency amplification and a peak tube voltmeter. By this means absorption constant values are obtained to three significant figures. Velocity measurements may be made to include four significant figures.

ISSN:0034-6748    

DOI:10.1063/1.1751958

出版商:AIP    

年代:1935

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751959

出版商:AIP    

年代:1935

数据来源: AIP