ISSN:0034-6748    

DOI:10.1063/1.1748769

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748770

出版商:AIP    

年代:1931

数据来源: AIP

摘要:

An apparatus is described which will automatically maintain a constant level in a bath of liquid air.

ISSN:0034-6748    

DOI:10.1063/1.1748771

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748772

出版商:AIP    

年代:1931

数据来源: AIP

摘要:

A method of measurement is used whereby variation in frequency of a high frequency oscillator can be measured easily to a fraction of a part in a million. The audible difference tone produced by a harmonic of a constant, high frequency oscillator and a harmonic of a second oscillator is compared to the tone of a variable, calibrated audio frequency oscillator. Any change of the frequency of the second high frequency oscillator is measured to a fraction of a cycle per second. This method of measurement is used to determine the effects of temperature and pressure on the frequency of a piezo‐electric oscillator. The temperature effect is of the order of 20 parts per million per degree centigrade while the pressure effect is of the order of only 6 parts per million per atmosphere.

ISSN:0034-6748    

DOI:10.1063/1.1748773

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748774

出版商:AIP    

年代:1931

数据来源: AIP

摘要:

A thermostat regulator has been constructed with a tungsten‐mercury contact in hydrogen permanently enclosed in glass. Adjustment is made by a mercury‐tight tungsten plunger in another 2 mm capillary, one complete turn of the micrometer head advancing the plunger approximately 1 mm, equivalent to 0.08°C. The contact breaks approximately 1 milliampere which actuates relays controlling the heating circuit of one ampere, 110 volts ac. The regulator kept a 50‐liter water thermostat constant to ±0.002°C, for an hour, with a 5‐minute regulation cycle. With an auxilary heater close to the regulator, the temperature variation was less than ±0.001°C over a period of three hours and the regulation cycle less than 1 minute.

ISSN:0034-6748    

DOI:10.1063/1.1748775

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748776

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748777

出版商:AIP    

年代:1931

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1748778

出版商:AIP    

年代:1931

数据来源: AIP