From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Paper on the use of neon lamps for stroboscopic work, reprinted from the Proceedings of the Cambridge Philosophical Society.
| Identifier | ExFiles\Box 79\1\ scan0257 | |
| Date | 19th February 1920 | |
| R.R. 288A (100 T) (S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643, 19-2-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2618 X.1601 EFC. NEON LAMPS FOR STROBOSCOPIC WORK. by F.{Mr Friese} W. Aston, M.A Trinity College (D.Sc.,Birmingham) Clerk-Maxwell Student of the University of Cambridge. Reprinted from the "Proceedings of the Cambridge Philosophical Society." Vol. XIX. Part Six. Cambridge. At the University Press. February 9th, 1920. Read 19th. May, 1919. For the accurate graduation and testing of revolution indicators and similar technical purposes the Stroboscopic method is probably the most reliable. This depends on the fact that if a rotating disc is illuminated N times per second by very short flashes, a regular figure drawn symmetrically on the disc will appear at rest when the number of revolutions of the disc per second is some exact multiple or submultiple of N depending on the number of sides of the regular figure. The value of N - in practice 50 - can be set and easily kept extremely constant by the use of an electrically driven tuning-fork so that the success of the method rests principally upon the illuminating flashes; its accuracy will depend upon their shortness of duration and brightness; its convenience as a practical method upon their brightness and quality as affecting the eye of the observer. The first experiments were tried with naked Leyden jar sparks obtained from the secondary of an ordinary ignition coil, the tuning-fork being introduced into the primary circuit as an interrupter. These showed the principle of the method to be excellent but spark illumination left much to be desired; it was noisy, feeble in intensity, and being mostly of short wave-length, caused rapid and excessive eye-strain even when used in a dark room. The remarkable properties of Neon seemed to offer an almost ideal solution of the illumination problem. A form of lamp replace the spark was therefore devised which appeared likely to give good results and several of these were filled from the author's stock of Neon at the Cavendish Laboratory. The success of these lamps was immediate, eye-strain disappearing completely. The present paper is a description of the lamps and their behaviour during continuous use. ( Contd.) | ||