- Email: [email protected]
Remote instrumentation best for jet planes
390
CURRENT TOPICS.
[J. F. I.
Remote Instrumentation B e s t For Jet Planes.--Instruments for jetplanes of the f u t u r e will be of the electrical remote-reading type for reasons of safety and ease of installation, in the opinion of C. A. E d m a n , of G e n e r a l Electric's M e t e r and I n s t r u m e n t Division. Speaking at a r e c e n t ASME meeting on the s u b j e c t of."Instrumentation for Jet-Propelled Airplanes," Mr. E d m a n explained that the low vibration inh e r e n t in jet engines permits the use of more delicate p r i m a r y detectors than does the reciprocating engine. H e said that d-c selsyn s y s t e m s u s i n g m o v a b l e contacts have a l r e a d y proved successful in a n u m b e r of jet p l a n e installations. " B e c a u s e of t h e i r size, however, t h e s e d-c selsyn s y s t e m s will d o u b t l e s s be superseded by the inherently smaller a-c t y p e s as soon as the proper r a n g e s are developed in the latter systems," E d m a n s a i d . Remote-reading instruments are virtually a " m u s t " for jet planes, according to Mr. E d m a n , b e c a u s e of the need for q u i c k disassembly of the engine from the airframe and the desirability of keeping high-pressure fuel lines o u t s i d e the c o c k p i t . The jet plane's gas-turbine engine n e e d s only five b a s i c indicating i n s t r u m e n t s , as compared with seven required by the conventional reciprocating engine, E d n i a n s a i d . T h e s e are the tachometer, tailpipe-temperature i n d i cator, bearing-temperature g a g e , oil-pressure g a g e , and fuel pressure g a g e . However, he pointed out, these instruments will need considerable improvement to meet the special conditions of jet e n g i n e indication. The most u r g e n t n e e d s are in tailpipipe-temperature and bearing-temperature indication. Instruments for these purposes will r e q u i r e improved resistance bulbs t o w i t h s t a n d high temperatures and corrosive atmosphere. R. H. O. P o w e r f u l Electro-Magnet Aids R e s e a r c h . (Power Plant Engineering, Vol. 50, No. 12.)--An electro-magnet so powerful that the operator m u s t stay at the controls four y a r d s a w a y when it is at peak operation in o r d e r to avoid having his pockets picked has been developed by Dr. J. E. G o l d m a n of the Westinghouse Research Laboratories. It is an oil-cooled, 1½ t., iron-core, electro-magnet w o u n d with 6000 turns of s q u a r e copper, w i r e d and tipped with a special m a g n e t i c alloy. The magnet, 5 ft. long and 2½ ft. high, has a d j u s t a b l e poles so that specimens from 1½ to 12 in. may be attracted and is c a p a b l e of exerting a concentrated 4000 lb. p u l l - - a force strong e n o u g h t o make possible new s t u d i e s in magnetism. One secret of the high m a g n e t i s m produced is the special a l l o y tips. This alloy was developed by the Westinghouse Research Laboratories to give more magnetic e n e r g y than ordinary iron. The variation in the gap b e t w e e n poles is accomplished by the use of adjustable tapered pole pieces. This feature adds immensely to the versatility of the magnet. R. H, OPPERMANN,
CURRENT TOPICS.
[J. F. I.
Remote Instrumentation B e s t For Jet Planes.--Instruments for jetplanes of the f u t u r e will be of the electrical remote-reading type for reasons of safety and ease of installation, in the opinion of C. A. E d m a n , of G e n e r a l Electric's M e t e r and I n s t r u m e n t Division. Speaking at a r e c e n t ASME meeting on the s u b j e c t of."Instrumentation for Jet-Propelled Airplanes," Mr. E d m a n explained that the low vibration inh e r e n t in jet engines permits the use of more delicate p r i m a r y detectors than does the reciprocating engine. H e said that d-c selsyn s y s t e m s u s i n g m o v a b l e contacts have a l r e a d y proved successful in a n u m b e r of jet p l a n e installations. " B e c a u s e of t h e i r size, however, t h e s e d-c selsyn s y s t e m s will d o u b t l e s s be superseded by the inherently smaller a-c t y p e s as soon as the proper r a n g e s are developed in the latter systems," E d m a n s a i d . Remote-reading instruments are virtually a " m u s t " for jet planes, according to Mr. E d m a n , b e c a u s e of the need for q u i c k disassembly of the engine from the airframe and the desirability of keeping high-pressure fuel lines o u t s i d e the c o c k p i t . The jet plane's gas-turbine engine n e e d s only five b a s i c indicating i n s t r u m e n t s , as compared with seven required by the conventional reciprocating engine, E d n i a n s a i d . T h e s e are the tachometer, tailpipe-temperature i n d i cator, bearing-temperature g a g e , oil-pressure g a g e , and fuel pressure g a g e . However, he pointed out, these instruments will need considerable improvement to meet the special conditions of jet e n g i n e indication. The most u r g e n t n e e d s are in tailpipipe-temperature and bearing-temperature indication. Instruments for these purposes will r e q u i r e improved resistance bulbs t o w i t h s t a n d high temperatures and corrosive atmosphere. R. H. O. P o w e r f u l Electro-Magnet Aids R e s e a r c h . (Power Plant Engineering, Vol. 50, No. 12.)--An electro-magnet so powerful that the operator m u s t stay at the controls four y a r d s a w a y when it is at peak operation in o r d e r to avoid having his pockets picked has been developed by Dr. J. E. G o l d m a n of the Westinghouse Research Laboratories. It is an oil-cooled, 1½ t., iron-core, electro-magnet w o u n d with 6000 turns of s q u a r e copper, w i r e d and tipped with a special m a g n e t i c alloy. The magnet, 5 ft. long and 2½ ft. high, has a d j u s t a b l e poles so that specimens from 1½ to 12 in. may be attracted and is c a p a b l e of exerting a concentrated 4000 lb. p u l l - - a force strong e n o u g h t o make possible new s t u d i e s in magnetism. One secret of the high m a g n e t i s m produced is the special a l l o y tips. This alloy was developed by the Westinghouse Research Laboratories to give more magnetic e n e r g y than ordinary iron. The variation in the gap b e t w e e n poles is accomplished by the use of adjustable tapered pole pieces. This feature adds immensely to the versatility of the magnet. R. H, OPPERMANN,