Accession Number : AD0824942

Title :   PIEZORESISTIVE TRANSDUCER FOR SHOCK WAVE STUDIES.

Descriptive Note : Technical rept. 11 Apr 66-10 May 67,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s) : Keough, D. D. ; Williams, R. F.

Report Date : DEC 1967

Pagination or Media Count : 74

Abstract : Two methods of measuring stress-time profiles using, manganin, a piezoresistive element, essentially within test materials, were examined theoretically and experimentally. One method involves two-dimensional flow and the other involves one-dimensional flow. The one-dimensional method perturbs the test medium least and, with appropriate insulators, is well suited for use with metallic specimens. Stresses up to 100 kbar were investigated. Recording durations of several micro-seconds were achieved. The piezoresistive coefficent of manganin, measured in an insulator of considerably higher shock impedance than that used in prior work, was equal to previous values. Vapor deposition of a manganin-like alloy with a film thickness of around 2000A was achieved. One experiment with this film yielded a positive piezoresistive coefficient of 0.22 x 0.01 omega/omega/kbar, some 20% less than that of commercially available manganin alloy. Field Test gages were constructed for the Midi Mist Event. Stress-resistance measurements were made on calcium, a low pressure, high sensitivity piezoresistive material. In the pressure range to 28 kbar a coefficient of 0.023 plus or minus 0.003 omega/omega/kbar was obtained. An experiment was conducted to verify calculations of heat flow between a sensitive thin-film and a surrounding insulator. The results show that the heat transfer rates are at least as high as those indicated by the calculations. (Author)

Descriptors :   (*SHOCK WAVES, MEASUREMENT), (*TRANSDUCERS, DETECTORS), STRESSES, FILMS, PRESSURE, ELECTRICAL RESISTANCE, PIEZOELECTRIC EFFECT, SENSITIVITY, ELECTRICAL IMPEDANCE, CALCIUM.

Subject Categories : Test Facilities, Equipment and Methods
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE