Patent · US Expired

Method and apparatus for characterizing materials by using a mechanical resonator

US6393895B1 · kind B1 · utility

74Cited by
50References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 12, 1998
Grant dateMay 28, 2002
Priority date
Expiry dateAug 12, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2291/0427
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a thickness shear mode resonator or a tuning fork resonator, connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the tuning fork, causing the mechanical resonator to oscillate. To test the properties of a liquid composition, the mechanical resonator is placed inside a sample well containing a small amount of the liquid. The input signal is then sent to the mechanical resonator and swept over a selected frequency range, preferably less than 1 MHz to prevent the liquid being tested from exhibiting gel-like characteristics and causing false readings. The mechanical resonator's response over the frequency range depends on various characteristics of the liquid being tested, such as the temperature, viscosity, and other physical properties. Particular mechanical resonators, such as tuning fork resonators, can also be used to measure a liquid composition's electrical properties, such as the dielectric constant and conductivity, because the tuning fork's structure allows a high degree of electrical coupling between the tuning…

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