Method and apparatus for characterizing materials by using a mechanical resonator

• US 20040074302A1
• Filed: 10/15/2003
• Published: 04/22/2004
• Est. Priority Date: 10/08/1997
• Status: Active Grant

• Current Assignee: Meas France
• Original Assignee: Symyx Technologies Incorporated (Dassault Systemes SA)
• Inventors: Bennett, James, Matsiev, Leonid, McFarland, Eric
• Granted Patent: US 6,957,565 B2
• Time in Patent Office: Days
• US Class Current: 73/579
• CPC Class Codes: B01J 2219/00704 integrated with the reactor apparatus
• CPC Class Codes: G01H 13/00 Measuring resonant frequency
• CPC Class Codes: G01N 11/16 by measuring damping effect upon oscillatory body
• CPC Class Codes: G01N 2009/006 vibrating tube, tuning fork
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 2291/0224 Mixtures of three or more liquids
• CPC Class Codes: G01N 2291/0255 (Bio)chemical reactions, e.g. on biosensors
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 2291/02818 Density, viscosity
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects
• CPC Class Codes: G01N 29/348 with frequency characteristics, e.g. single frequency signals, chirp signals measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: G01N 29/4418 with a model, e.g. best-fit, regression analysis
• CPC Class Codes: G01N 29/4427 with stored values, e.g. threshold values
• CPC Class Codes: G01N 29/4436 with a reference signal amplitude comparison G01N29/48
• CPC Class Codes: G01N 9/002 : using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis G01N9/34 takes precedence
• CPC Class Codes: G01N 9/34 : by using elements moving through the fluid, e.g. vane
• CPC Class Codes: G10K 11/02 : Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators

Abstract

A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a cantilever, connected to a measurement circuit. The mechanical resonator can be covered with a coating to impart additional special detection propertied to the resonator, and multiple resonators can be attached together as a single sensor to obtain multiple frequency responses. The invention is particularly suitable for combinatorial chemistry applications, which require rapid analysis of chemical properties for screening.

Claims

1. :

A method for in-line monitoring of a fluid composition, the method comprising;

placing a tuning fork resonator in contact with the fluid composition in a conduit;

oscillating the resonator while the fluid composition is flowing the conduit;

monitoring the resonator to obtain a resonator response; and

determining at least two properties of the fluid composition based on the resonator response.

2. :

The method of claim 1, wherein the at least two properties are selected from the group consisting of viscosity, density, viscosity density product, molecular weight, specific weight, elasticity, dielectric constant, conductivity.

3. :

The method of claim 2, wherein the at least two properties are simultaneously determined based on the resonator response.

4. :

The method of claim 2, wherein the at least two properties are separately determined based on the resonator response.

5. :

The method of claim 2, wherein the at least two properties are viscosity and density.

6. :

The method of claim 2, wherein the at least two properties are viscosity and dielectric constant.

7. :

The method of claim 2, wherein the separately determining step included separately determining at least three properties of the fluid composition.

8. :

The method of claim 7, wherein the at least three properties are viscosity, dielectric constant and conductivity.

9. :

The method of claim 2, further comprising;

calibrating the resonator against a standard fluid or a number of standard fluids having known properties to obtain calibration data; and

determining the at least two properties based on the calibration data and the resonator response.

10. :

The method of claim 9, wherein the conduit is an oil pipeline.

11. :

A method for in-line monitoring of a fluid composition, the method comprising;

calibrating a tuning fork resonator against a standard fluid or a number of standard fluids having known properties to obtain calibration data;

placing the resonator in contact with the fluid composition in a conduit;

oscillating the resonator while the fluid composition is flowing the conduit;

monitoring the resonator to obtain a resonator response; and

simultaneously determining at least two properties based on the calibration data and the resonator response.

12. :

The method of claim 11, wherein the at least two properties are viscosity and density.

13. :

The method of claim 11, wherein the at least two properties are viscosity and dielectric constant.