摘要:

The evaluation of photographic line patterns is discussed with the object of comparing various procedures in their relation to the design of a microdensitometer. While some of the points discussed apply to the evaluation of optical spectra, the main interest of the discussion is directed towards setting out the various requirements which arise in the evaluation of x‐ray patterns. The second part of the paper describes a microdensitometer designed to conform with some of these requirements.

ISSN:0034-6748    

DOI:10.1063/1.1770298

出版商:AIP    

年代:1945

数据来源: AIP

摘要:

Comparative performances of Litton C, Octoil, Narcoil, and two typical silicones in a non‐fractionating diffusion pump are presented with a discussion of vapor pressure, stability to heat and oxidation, and the ability to operate against high forepressures. Extrapolated vapor pressure, temperature data, and test results show the high boiling silicone to produce the highest vacuum as indicated by an untrapped ionization gauge. The silicon was further found to be nearly completely resistant to oxidation when exposed to air while hot. A table showing relative merits of various oils, as applied to vacuum pumping conditions ordinarily encountered, is presented.

ISSN:0034-6748    

DOI:10.1063/1.1770299

出版商:AIP    

年代:1945

数据来源: AIP

摘要:

A completely automatic recording Wheatstone bridge is designed especially for use in resistance thermometry. It is built into a standard commercial recorder, contains decade coils operated by a Geneva gear mechanism, and increases the original range of the machine 100‐fold. With it a continuous record of resistanceversustime is made covering a range of 0 to 100 ohms that may be easily read to 0.001 ohm±0.001 ohm. Employed in connection with a standard 25‐ohm platinum resistance thermometer a temperature range of −190° to 550°C can be covered with a precision of 0.01°C±0.01°.

ISSN:0034-6748    

DOI:10.1063/1.1770300

出版商:AIP    

年代:1945

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770303

出版商:AIP    

年代:1945

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770304

出版商:AIP    

年代:1945

数据来源: AIP