US 7,095,224 B2Granted

Process control and damage monitoring

AssigneeJENTEK Sensors, Inc.

InventorsNeil J. Goldfine, Darrell E. Schlicker, Andrew P. Washabaugh, David C. Grundy, Vladimir A. Zilberstein

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Abstract

A process control method is described which uses measurements from magnetic field sensors to monitor the condition of material, such as from a heat treatment process. The sensors can be single element sensors or sensor arrays, can be used to periodically inspect selected locations, mounted to the test material, or scanned over the test material to generate two-dimensional images of the material properties. The sensors can be exposed to the same process conditions as the material, such as elevated temperatures, or the shielding layers can be placed between the test material and the sensors to reduce sensor exposure to the processing conditions. Additional property measurements, such as sensor lift-off, can be used to ensure proper sensors operation.

Claims37

Dependent claims

A method for calibrating a sensor for use in process control, said method comprising:

disposing an electromagnetic field sensor proximate to a material that has at least one electrical property that varies with a process condition, the electromagnetic sensor being sensitive to the at least one electrical property;
disposing a material state sensor proximate to a test material, the material state being temperature;
measuring the material state sensor at two or more different states to calibrate the electromagnetic field sensor response based on a relationship between the electrical property and the material state, using the calibrated electromagnetic sensor response as an input to a process controller;
and
monitoring the relationship between a process condition and the electromagnetic sensor response to detect changes in the relationship between the electrical property and the material state caused by the process, said changes in the relationship being input to a process controller.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/762,193Filed 21 Jan 2004 · us provisional application
Priority: 21 Jan 2003
Published: US 2004/0174157 A19 Sep 2004
Granted: 22 Aug 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G01N 27/9046
Using eddy currents: by analysing electrical signals
G01N 27/904
Using eddy currents: with two or more sensors
G01N
Investigating or analysing materials by determining their chemical or physical properties