Volume 3, Issue 1, January 1932
Index of content:
3(1932); http://dx.doi.org/10.1063/1.1748828View Description Hide Description
The Exhibit of Testing Apparatus and Machines Held in Connection with the 34th Annual Meeting of the A.S.T.M.3(1932); http://dx.doi.org/10.1063/1.1748864View Description Hide Description
A DEVICE TO MEASURE THE AMOUNT OF PLANE POLARIZED LIGHT IN LOW INTENSITY RADIATIONS AND TO MEASURE SMALL ROTATIONS OF THE PLANE OF POLARIZATION3(1932); http://dx.doi.org/10.1063/1.1748830View Description Hide Description
To investigate polarizationproperties of radiations too weak to be handled with the common visual devices for the purpose, a photoelectric device is used. A nicol of good quality, with end faces perpendicular to the length is mounted on a caesium vacuum cell, and this, together with the working tube of a two tube bridge amplifier, placed in a brass container free to rotate about an axis passing through the center of the nicol. Control apparatus and the dummy tube and batteries are located in a stationary container, connections being made through a flexible shielded cable. The galvanometer deflection obtained is proportional to the intensity of the component of the radiation able to pass through the nicol. The percent of polarization has been measured with illuminations down to 10−5 foot‐candles. When applied to rotation measurements, a rotation of the plane of polarization of one second of arc can be detected.
3(1932); http://dx.doi.org/10.1063/1.1748832View Description Hide Description
3(1932); http://dx.doi.org/10.1063/1.1748833View Description Hide Description
A penta prism placed before the slit of a spectroscope eliminates the objections to this method of simultaneously observing the comparison and unknown spectra.
The penta comparison prism is preferably mounted on a vertical slide before the slit instead of on the usual hinged bracket.
3(1932); http://dx.doi.org/10.1063/1.1748863View Description Hide Description