Patent · US Expired

System for measuring stress

US5563348A · kind A · utility

7Cited by
11References
10Claims
0Family size

Inventors

Key dates

Filing dateSep 13, 1994
Grant dateOct 8, 1996
Priority date
Expiry dateSep 13, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01L1/103
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In a stress measuring, system sensor driving power and a signal sensed by a sensor are transmitted and received in the form of a light pulse signal to thereby improve a noise resistant property as well as a measuring accuracy and reliability. The stress measuring system includes a sensor head disposed at a sensing location and a measuring device disposed at a location remote from the sensing location. The sensor head includes a sensor having a sensing section for sensing a change in stress as a change in the natural frequency of an oscillation string, an output section for outputting a light pulse sensing signal corresponding to the natural frequency sensed by the sensing section and a driving section for causing oscillation at the natural frequency of the oscillation system of the sensing section in response to a driving light pulse signal. The measuring device includes a measuring section for measuring the stress based on the frequency of the light pulse sensing signal and a creating section for creating the driving light pulse signal having the frequency following a change in the natural frequency based on the light pulse sensing signal. The sensor head is connected to the measu…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.