Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrometer
Patent
1997-11-27
2000-10-03
Kim, Robert
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrometer
356432, G01B 902
Patent
active
06128081&
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to methods and systems for measuring a physical parameter of at least one layer of a multilayer article and sensor head for use therein and, in particular, to laser ultrasonic methods and systems for measuring a physical parameter such as thickness of a solid or liquid film formed on an article without damaging the film and a sensor head for use therein.
BACKGROUND ART
In any coating process of an article of manufacture such as an automotive body, there is an optimum specification for the resulting film build, i.e., thickness of the resulting coating layer involving acceptable performance, appearance and materials cost. The ability to measure this film build on-line in a production environment would be beneficial to the manufacturer.
Often, any method for measuring the film build of a coating layer must require that no contact with the film occur either to avoid degrading the effectiveness or marring the appearance of the film.. This is especially true for coatings while they are wet.
With manufacturing film build data, the bulk materials costs can be controlled by applying the minimum amount of material to reach an acceptable film build. Other savings can also be realized, for example measuring and improving the transfer efficiency of the coating process and correlating film build to the quality of the appearance of the final coated surface. An example process and production environment that would benefit from the ability to measure film build on-line is the painting of automobile bodies.
In automated painting operations, a prime concern is the reduction of environmental impacts due to the evaporation of solvents. Means of reducing the amount of solvent released into the atmosphere include electrostatic application of the paint and the use of waterborne paints. Electrostatic application increases the quantity of paint delivered to the painted object, and thus reduces the total quantity of paint required due to the decrease in overspray. The use of waterborne paints dramatically reduces the quantity of solvent utilized in the paint because water is used as a vehicle for paint delivery rather than solvent. Environmental concerns may dictate the exclusive use of waterborne paints in the future.
In order to further reduce waste, thus reducing solvent emissions, and to improve the quality of the finished painted article, it may be necessary to monitor or sense various paint physical parameters such as thickness with precision to effect control.
Waterborne paints are electrically conductive and, therefore, must be isolated from the environment such that an electrostatic charge may be imparted to the flow of paint. This isolation must be at least 100 kilovolts. Further, the painting environment is a hazardous environment due to the few remaining solvents in the paint. Therefore, any device which meters or measures the physical parameters of paint must provide electrostatic isolation and limit energies within the painting environment to less than that required for ignition.
The painting process for automobiles involves applying several coatings of different materials to an underlying metal or plastic substrate 10. As illustrated in FIG. 1, these coatings may include various anticorrosion layers such as a phosphate layer 12, an E-coat layer 14, primer layer(s) 16, colored paint layers 18 (referred to as base coats), and a transparent protective and appearance improving material(s) called a clearcoat 20. The ability to measure both total film build, i.e., the total thickness of all layers and/or the thickness of each individual layer, in both the wet or dry states would be useful.
One non-contact method for measuring solid film thickness and/or other physical properties of the film is provided by ultrasound generation in the film and subsequent ultrasound detection. However, this method typically locally damages or destroys the film.
For example, U.S. Pat. No. 4,659,224 discloses optical interferometric reception of ultrasound energy using a confocal Fabry-Perot int
REFERENCES:
patent: 3580056 (1971-05-01), Warner
patent: 4379226 (1983-04-01), Sichling et al.
patent: 4452082 (1984-06-01), Miwa
patent: 4522510 (1985-06-01), Rosencwaig et al.
patent: 4625556 (1986-12-01), Sukahara et al.
patent: 4659224 (1987-04-01), Monchalin
patent: 4704905 (1987-11-01), Arora
patent: 4709357 (1987-11-01), Maki, Jr.
patent: 4710030 (1987-12-01), Tauc et al.
patent: 5033304 (1991-07-01), Rosen
patent: 5035144 (1991-07-01), Aussel
patent: 5137361 (1992-08-01), Heon et al.
patent: 5271274 (1993-12-01), Khuri-Yakub et al.
patent: 5305239 (1994-04-01), Kinra
patent: 5402235 (1995-03-01), Monchalin
patent: 5590090 (1996-12-01), Duggal et al.
patent: 5604592 (1997-02-01), Kotidis et al.
patent: 5615675 (1997-04-01), O'Donnell et al.
patent: 5663502 (1997-09-01), Nagashima et al.
Estimating the Parameters of Exponentially Damped Sinusoids and Pole-Zero Modeling in Noise, by Ramdas Kumaresan & Donald W. Tufts, IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASP-30, No. 6, Dec. 1982.
Dixon John W.
LaPlant Frederick P.
White Jeffrey S.
Kim Robert
Perceptron, Inc.
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