The calculation of the shadow factor of single coil filament
A computer method for calculating the power-reduction factor of a single-coil filament is presented. The filament of incandescent lamps is coiled, which is why a fraction of radiation is trapped in the filament. The relationships between the geometric parameters of a cylindrical helix (pitch ratio and mandrel ratio) and the shadow factor are developed. A FORTRAN program based on the numerical solution of algebraic equations and on three-dimensional numerical integration has been developed.<<ETX>>
The Effect of Coil Pitch and Wire Diameter Variations on Incandescent Filament Behavior
The author presents a theoretical treatment of burnout of coiled filaments containing “hot spots” caused by wire diameter or coil pitch defects. Comparison with experimental measurements suggests that filament failure appears to be caused, in most cases, by pitch defects rather than wire diameter defects.
Calculations of power loss to the gas-filling of incandescent lamps
of its estimated departure from a maximally grey neutral stimulus. If so, the loci of constant greyness should plot as spheres in Uniform Colour Space and thus offer a ready-made basis for assessing the various uniform colour systems. The conclusions are ’to be treated with caution in view of the limited number of samples used and the poor control over the quantity and quality of the incident light. It is hoped, however, that the potential significance of these tentative conclusions may encourage others to repeat the observations under more refined conditions.