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Title: Method and apparatus for sensing the natural frequency of a cantilevered body

Abstract

A method and apparatus for measuring the natural resonant frequency of a spring element by monitoring a phase difference between an output signal from the spring element and an input signal to the spring element and by adjusting frequency of the input signal until a detected phase difference signals that the natural resonant frequency has been reached. The method and apparatus are applied to a micro-cantilevered elements used to measure gas compositions and concentrations. Such elements are provided with coatings that absorb gas to cause deflections and changes in the mass or spring constant of the cantilevered element. These changes correspond to changes in the natural resonant frequency of the cantilevered element which are measured using the method and apparatus described herein.

Inventors:
 [1]
  1. Clinton, TN
Issue Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
OSTI Identifier:
872926
Patent Number(s):
6041642
Assignee:
Lockheed Martin Energy Systems, Inc. (Oak Ridge, TN)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01G - WEIGHING
G - PHYSICS G01 - MEASURING G01H - MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; sensing; natural; frequency; cantilevered; measuring; resonant; spring; element; monitoring; phase; difference; output; signal; input; adjusting; detected; signals; reached; applied; micro-cantilevered; elements; measure; gas; compositions; concentrations; provided; coatings; absorb; deflections; changes; mass; constant; correspond; measured; described; natural frequency; gas composition; difference signal; phase difference; spring element; resonant frequency; output signal; input signal; spring constant; detected phase; difference signals; /73/422/

Citation Formats

Duncan, Michael G. Method and apparatus for sensing the natural frequency of a cantilevered body. United States: N. p., 2000. Web.
Duncan, Michael G. Method and apparatus for sensing the natural frequency of a cantilevered body. United States.
Duncan, Michael G. Sat . "Method and apparatus for sensing the natural frequency of a cantilevered body". United States. https://www.osti.gov/servlets/purl/872926.
@article{osti_872926,
title = {Method and apparatus for sensing the natural frequency of a cantilevered body},
author = {Duncan, Michael G},
abstractNote = {A method and apparatus for measuring the natural resonant frequency of a spring element by monitoring a phase difference between an output signal from the spring element and an input signal to the spring element and by adjusting frequency of the input signal until a detected phase difference signals that the natural resonant frequency has been reached. The method and apparatus are applied to a micro-cantilevered elements used to measure gas compositions and concentrations. Such elements are provided with coatings that absorb gas to cause deflections and changes in the mass or spring constant of the cantilevered element. These changes correspond to changes in the natural resonant frequency of the cantilevered element which are measured using the method and apparatus described herein.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}