# US 5,347,872 A · Magnetomechanical sensor attachment method

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,347,872 A
- Document ID: US5347872A
- Status: Granted
- Kind: A
- Application number: 06/900,045
- Filed: 1986-08-25
- Granted: 1994-09-20
- Earliest claimed: 1986-08-25
- Assignees: The United States of America as represented by the Secretary of the Navy
- Inventors: Arthur E. Clark
- Web page: https://patentgrep.com/patent/US5347872A

## CPC

- G01B 7/24: using change in magnetic properties
- Y10S 73/02: Magnetostrictive
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A method of measuring strain in material by (1) selecting a metallic glass ribbon of the composition Fe.sub.w B.sub.x Si.sub.y C.sub.z wherein 0.70.ltoreq.w.ltoreq.0.83, 0.10.ltoreq.x.ltoreq.0.20, 0.03.ltoreq.y.ltoreq.0.10, 0.ltoreq.z.ltoreq.0.03, and w+x+y+z=1.00 wherein the metallic glass ribbon is essentially strain free and has easy xes of magnetization which are in the plane of the ribbon transverse (at 90.degree.) to the long axis of the ribbon; (2) bonding the metallic glass ribbon to material to be measured by means of a homogeneous viscous organic liquid having a viscosity greater than 10.sup.5 cp at 25.degree. C.; (3) allowing the viscous liquid to relax until the metallic glass ribbon is not stressed by the viscous liquid and is in a state of constant strain within it magnetostrictive dynamic range; and (4) measuring the susceptibility of the metallic glass ribbon which is directly proportional to strain within the material being measured.

## Claims

### Claim 1

A method for measuring strain in a material object comprising the steps of
(1) selecting a metallic glass ribbon of the composition
Fe.sub.w B.sub.x Si.sub.y C.sub.z
wherein
0.70.ltoreq.w.ltoreq.0.83,
0.10.ltoreq.x.ltoreq.0.20,
0.03.ltoreq.y.ltoreq.0.10,
0.ltoreq.z.ltoreq.0.03, and
w+x+y+z=1.00
wherein the metallic glass ribbon is essentially strain free and has easy axes of magnetization which are in the plane of the ribbon transverse (at 90.degree.) to the long axis of the ribbon;
(2) bonding the metallic glass ribbon to the material object by means of a homogeneous viscous organic liquid having a viscosity greater than 10.sup.5 cp at 25.degree. C.;
(3) allowing the viscous liquid to relax until the metallic glass ribbon is not stressed by the viscous liquid and is in a state of constant strain within its magnetostrictive dynamic range; and
(4) measuring the susceptibility of the metallic glass ribbon which is directly proportional to strain within the material being measured.

### Claim 2 (depends on 1)

The method of claim 1 wherein the homogeneous viscous organic liquid is heated until it is flowable before being applied in step (2) of claim 1 and the metallic glass ribbon then is held in place against the material object while the liquid cools to ambient temperature.

### Claim 3 (depends on 1)

The method of claim 1 wherein the homogeneous viscous organic liquid has a viscosity of from 10.sup.6 to 10.sup.8 cp at 25.degree. C.

### Claim 4 (depends on 3)

The method of claim 3 wherein the homogeneous viscous organic liquid has a viscosity of approximately 10.sup.7 cp at 25.degree. C.

### Claim 5 (depends on 1)

The method of claim 1 wherein the homogeneous viscous organic liquid is a mixture of polychloronated biphenyls.

### Claim 6 (depends on 5)

The method of claim 5 wherein the mixture of polychloronated biphenyls is from 60 to 64 percent by weight chlorine.

### Claim 7 (depends on 6)

The method of claim 6 wherein the mixture of polychloronated biphenyls is from 61 to 63 percent by weight chlorine.

### Claim 8 (depends on 7)

The method of claim 7 wherein the mixture of polychloronated biphenyls is approximately 62 percent by weight chlorine.

### Claim 9 (depends on 1)

The method according to claim 1 wherein 0.79.ltoreq.w.ltoreq.0.82.

### Claim 10 (depends on 1)

The method according to claim 1 wherein 0.135.ltoreq.x.ltoreq.0.15.

### Claim 11 (depends on 1)

The method according to claim 1 wherein 0.03.ltoreq.y.ltoreq.0.06.

### Claim 12 (depends on 1)

The method according to claim 1 wherein 0.ltoreq.z.ltoreq.0.02.