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Title: Method and apparatus for monitoring and measuring the surface tension of a fluid using fiber optics

Abstract

A non-contact method and apparatus for measuring and monitoring the surface of a fluid using fiber optics and interferometric detection to permit measurement mechanical characteristics' fluid surfaces. The apparatus employs an alternating electric field gradient for generating a capillary wave on the surface of the fluid. A fiber optic coupler and optical fiber directs a portion of a laser beam onto the surface of the fluid, another portion of the laser beam onto the photo sensor, and directs light reflected from the surface of the fluid onto the photo sensor. The output of the photo sensor is processed and coupled to a phase sensitive detector to permit measurement of phase shift between the drive signal creating the capillary wave and the detected signal. This phase shift information is then used to determine mechanical properties of the fluid surface such as surface tension, surface elasticity, and surface inhomogeneity. The resulting test structure is easily made compact, portable, and easy to align and use.

Inventors:
 [1];  [2];  [2];  [2]
  1. Oak Park, IL
  2. Evanston, IL
Issue Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
OSTI Identifier:
869238
Patent Number(s):
5303030
Assignee:
Northwestern University (Evanston, IL)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
DOE Contract Number:  
FG02-84ER45125
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; monitoring; measuring; surface; tension; fluid; fiber; optics; non-contact; interferometric; detection; permit; measurement; mechanical; characteristics; surfaces; employs; alternating; electric; field; gradient; generating; capillary; wave; optic; coupler; optical; directs; portion; laser; beam; photo; sensor; light; reflected; output; processed; coupled; phase; sensitive; detector; shift; drive; signal; creating; detected; information; determine; properties; elasticity; inhomogeneity; resulting; structure; easily; compact; portable; easy; align; mechanical characteristics; apparatus employs; field gradient; light reflected; fiber optics; phase shift; electric field; fiber optic; laser beam; optical fiber; mechanical properties; surface tension; detected signal; sensitive detector; alternating electric; phase sensitive; drive signal; directs light; interferometric detection; capillary wave; /356/

Citation Formats

Abraham, Bernard M, Ketterson, John B, Bohanon, Thomas M, and Mikrut, John M. Method and apparatus for monitoring and measuring the surface tension of a fluid using fiber optics. United States: N. p., 1994. Web.
Abraham, Bernard M, Ketterson, John B, Bohanon, Thomas M, & Mikrut, John M. Method and apparatus for monitoring and measuring the surface tension of a fluid using fiber optics. United States.
Abraham, Bernard M, Ketterson, John B, Bohanon, Thomas M, and Mikrut, John M. Sat . "Method and apparatus for monitoring and measuring the surface tension of a fluid using fiber optics". United States. https://www.osti.gov/servlets/purl/869238.
@article{osti_869238,
title = {Method and apparatus for monitoring and measuring the surface tension of a fluid using fiber optics},
author = {Abraham, Bernard M and Ketterson, John B and Bohanon, Thomas M and Mikrut, John M},
abstractNote = {A non-contact method and apparatus for measuring and monitoring the surface of a fluid using fiber optics and interferometric detection to permit measurement mechanical characteristics' fluid surfaces. The apparatus employs an alternating electric field gradient for generating a capillary wave on the surface of the fluid. A fiber optic coupler and optical fiber directs a portion of a laser beam onto the surface of the fluid, another portion of the laser beam onto the photo sensor, and directs light reflected from the surface of the fluid onto the photo sensor. The output of the photo sensor is processed and coupled to a phase sensitive detector to permit measurement of phase shift between the drive signal creating the capillary wave and the detected signal. This phase shift information is then used to determine mechanical properties of the fluid surface such as surface tension, surface elasticity, and surface inhomogeneity. The resulting test structure is easily made compact, portable, and easy to align and use.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {1}
}

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Works referenced in this record:

Static and dynamic properties of pentadecanoic acid monolayers at the air-water interface
journal, May 1986


A study of the mechanical behavior of surface monolayers using orthogonal Wilhelmy plates
journal, January 1989


Novel technique for dynamic surface tension and viscosity measurements at liquid–gas interfaces
journal, October 1978