Volume 2, Issue 12, December 1931
Index of content:
2(1931); http://dx.doi.org/10.1063/1.1748752View Description Hide Description
A new high vacuum pumping system is described in which oil* is used in a diffusion type pump, and a trap containing activated cocoanut charcoal replaces the usual liquid air trap. The system is capable of attaining a pressure of 2×10−8 mm Hg. A high degree of vacuum can be attained at least as quickly as with a mercurydiffusion pump and liquid air trap. The system is especially adapted to maintaining a low pressure for several days in apparatus which cannot conveniently be sealed off from the pumps.
2(1931); http://dx.doi.org/10.1063/1.1748753View Description Hide Description
M. Eppley,1 studying the relation between the degree of saturation and the emf, and the temperature coefficient of emf on acid unsaturated standard cells acidified to 0.012 mol per litre of sulphuric acid, has concluded that the acid unsaturated cells with cadmium sulphate concentration of 42.93 percent have negligible temperature coefficients between 15° and 35°C, and that the solutions of these cells might have been saturated at about 4°C.
The present authors2 measured, in the first place, the solubility of cadmium sulphate into dilute sulphuric acid at different concentrations, and based on the obtained results, with electrolytes of various concentrations from dilute to nearly saturated solutions of cadmium sulphate. They attempted to find out the optimum concentration of cadmium sulphate and acidity of electrolyte, estimated from every point of view, and concluded that cells of concentration of cadmium sulphate 43.0 percent and of acidity 0.05N are most suitable.
2(1931); http://dx.doi.org/10.1063/1.1748754View Description Hide Description
The terms power sensitivity and voltage sensitivity are defined for photoelectric elements in a circuit, and a mathematical expression is derived to evaluate each of these characteristics for the three classes of light‐sensitive devices. Curves are plotted for comparing the outputs with one another for various intensities of light flux.
2(1931); http://dx.doi.org/10.1063/1.1748756View Description Hide Description
2(1931); http://dx.doi.org/10.1063/1.1748757View Description Hide Description
2(1931); http://dx.doi.org/10.1063/1.1748758View Description Hide Description
2(1931); http://dx.doi.org/10.1063/1.1748760View Description Hide Description