Accession Number : AD0696586
Title : DESIGN AND DEVELOPMENT OF AN ISOTOPIC ALTIMETER SETTING INDICATOR. VOLUME II. APPENDIXES.
Descriptive Note : Final rept.,
Corporate Author : PANAMETRICS INC WALTHAM MASS
Personal Author(s) : Sellers,B. ; Morel,P.
Report Date : JUN 1969
Pagination or Media Count : 89
Abstract : Design and development of an altimeter setting indicator system based on use of a radioactive alpha particle emitter as the primary sensing mechanism is described. Because the isotope measures density, a controlled temperature enclosure is utilized to provide an output proportional to pressure. The system uses a computer controlled closed loop servo to maintain the source at the 'constant range' position with respect to the detector. A shaft encoder maintains continuous knowledge of the actual source-detector distance, by which the pressure is deduced from a calibration curve. The altimeter setting indicator is calculated by the computer and displayed digitally. In its present form the system does not meet the design objective accuracy of plus or minus 0.005 inches of mercury. It is believed, however, that when temperature instabilities are corrected this objective will be achieved. (Author)
Descriptors : (*ALTIMETERS, GROUND POSITION INDICATORS), (*DETECTORS, *COUNT RATE METERS), RADIOACTIVE ISOTOPES, DENSIMETERS, PRESSURE VESSELS, TEMPERATURE CONTROL, SAMPLERS, RELIABILITY, TEST METHODS, DRIVES, ELECTRONIC EQUIPMENT, SERVOMECHANISMS, COMPUTER PROGRAMS, CONTROL SYSTEMS
Subject Categories : Flight Control and Instrumentation
Distribution Statement : APPROVED FOR PUBLIC RELEASE