Properties of Low Intensity Reflecting Arc Projector Carbons

The characteristics of the latest type of low intensity reflecting arc carbons (which are capable of burning at higher currents than those previously available) are presented. These include current capacity, candle-power, angular light distribution, crater diameter, and intrinsic brilliancy. — These characteristics are discussed in relation to the optical system. It is shown that although the maximum screen light from the present optical system as determined by photometric measurements can be obtained at a comparatively low current, there are decided practical advantages in using a higher current and larger carbons than the minimum theoretically possible. — It is also demonstrated that the faster projection lenses now available, together with a change in the magnification of the reflector system, should make possible an increase of theoretically 75 per cent in screen light over that now available with the present system. This increased screen light will have the same uniformity, flexibility, and factor of safety as that now obtained, provided the correct carbons and currents are used.

Print ISSN

0097-5834

Published

1931-06

Content type

Original Research

DOI

10.5594/J08042