Accession Number : AD0664199

Title :   RADIOISOTOPE EMITTER FOR NUCLEAR BAROMETER.

Descriptive Note : Final rept. no. 1, 1 Jul 66-30 Jun 67,

Corporate Author : PANAMETRICS INC WALTHAM MASS

Personal Author(s) : Sellers,Bach

Report Date : DEC 1967

Pagination or Media Count : 66

Abstract : A need exists in the U. S. Army for a practical field barometer having response time of a few seconds and operating in the range of 550-1060 millibars. It is shown that a technique involving alpha attenuation in a variable source-detector distance configuration is capable of measuring to 0.1 mb in the specified range. As a result of the peculiar effect of hydrogen on the attenuation process, however, it is necessary that the dew point in the measuring cavity be held below -15C in order that the calibration of count rate versus density be independent of dew point, assuming that the density is calculated taking dew point into account. If no dew point measurement is made, it is necessary that calculation of density be made without knowing the moisture content of the air. This requires that the dew point be less than -50C in order that the density be calculable with the desired accuracy. (Author)

Descriptors :   (*BAROMETERS, *RADIATION MEASURING INSTRUMENTS), (*DENSITOMETERS, RADIATION MEASURING INSTRUMENTS), ALPHA PARTICLES, BETA PARTICLES, ATTENUATION, RADIOACTIVE ISOTOPES, AMERICIUM, BAROMETRIC PRESSURE, DEW POINT

Subject Categories : Meteorology
      Test Facilities, Equipment and Methods
      Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE