Method for stress assessment that removes temperature effects and hysteresis on the material property measurements

US8415947B2 · kind B2 · utility

Assignee

• JENTEK Sensors, Inc. · US

Inventors

• Yanko K. Sheiretov · Waltham, US
• Neil J. Goldfine · Newton, US
• Todd M Dunford · Amherst, US
• Scott Denenberg · Boston, US
• David C. Grundy · Reading, US
• Darrell E. Schlicker · Watertown, US
• Andrew P. Washabaugh · Chula Vista, US
• Karen E. Walrath · Arlington, US

Key dates

• Filing date: Jul 16, 2012
• Grant date: Apr 9, 2013
• Expiry date: Jul 16, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L5/164
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus for the nondestructive measurement of materials that includes at least two layers of electrical conductors. Within each layer, a meandering primary winding is used to create a magnetic field for interrogating a test material while sense elements or conducting loops within each meander provide a directional measurement of the test material condition. In successive layers extended portions of the meanders are rotated so that the sense elements provide material condition in different orientations without requiring movement of the test circuit or apparatus. Multidirectional permeability measurements are used to assess the stress or torque on a component. These measurements are combined in a manner that removes temperature effects and hysteresis on the property measurements. This can be accomplished through a correction factor that accounts for the temperature dependence.