Accession Number : AD0270220

Title :   NOTES ON THE STUDY AND EVALUATION OF POSITION DETERMINATION SUB-SYSTEMS

Corporate Author : NATIONAL AVIATION FACILITIES EXPERIMENTAL CENTER ATLANTIC CITY N J

Personal Author(s) : KESTER,ROBERT E.

Report Date : 24 FEB 1961

Pagination or Media Count : 1

Abstract : DESCRIPTORS: (Soli state physics, Electrical properties, Piezoelectric effect, Crystals, *Barium comp un s, *Titanates, *Crystal struc ture.) (Particles, Heat treatment, Processing, Chemical analysis Spectrographic analysis, Phase studies.) (T ESTS, *Thermal expansion, Density, Physical properties.) The electrical properties, especially t e piezoelectric, are epen ent n t only upon the chemical composition of BaTiO3 but also upon the BaTiO3 compounds and unreacted materials present. Some of these properties persisted even after ceramic firing of the test pieces fabricated from the powders. The piezoelectric couplings ere measure . There was n direct correlation between t e coupling and t e density of the material over a wide temperature range. The effects of grain size and grain-size distribution on various parameters of fired BaTiO3 samples are c pared graphically with the as-received or the as-prepared materials. Thermal expansion tests showed that expansion characteristics of BaTiO3 from different rces did not nece arily differ rom eac ot er any m re t an i different lots from the same source. T HE COE FICIENT OF EXPANSION ECREASED ABRUPTLY AT THE Curie Point and t en increased rapi ly. (Author)

Descriptors :   *AIR TRAFFIC CONTROL SYSTEMS, AIR CONTROL CENTERS, AIRCRAFT, POSITION FINDING, RELIABILITY, TEST METHODS

Distribution Statement : APPROVED FOR PUBLIC RELEASE