Thermomagnetic temperature sensing

Patent metadata

Field	Value
Publication number	US-9719863-B1
Application number	US-201414194724-A
Country	US
Kind code	B1
Filing date	Mar 1, 2014
Priority date	Mar 15, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A thermomagnetic sensor, measurement system and a method of measuring temperature employ a thermomagnetic probe to measure temperature of a device using a thermomagnetic effect. The thermomagnetic sensor includes a plurality of coils configured to provide a mutual inductance measurement between a selected pair of coils of the plurality and the thermomagnetic probe between the selected pair. The thermomagnetic probe includes a ferromagnetic material having a temperature-dependent magnetic permeability determined from the mutual inductance measurement. A predetermined relationship between the temperature-dependent magnetic permeability and temperature in a range between a maximum magnetic permeability value and a Curie temperature provides a measurement of a temperature local to the thermomagnetic probe.

First claim

What is claimed is:

1. A thermomagnetic sensor comprising:
a plurality of coils spaced apart from one another and configured to provide a mutual inductance measurement between a selected pair of the coils of the plurality; and
a thermomagnetic probe structurally configured inside a device in which an internal temperature of the device is to be remotely measured, the plurality of coils being arranged external to the device and physically spaced apart from the thermomagnetic probe such that the thermomagnetic probe is spatially located between the selected pair of coils, the thermomagnetic probe comprising a ferromagnetic material having a temperature-dependent magnetic permeability characterized by a maximum value at a temperature below a Curie temperature of the ferromagnetic material, the temperature-dependent magnetic permeability monotonically decreasing as a function of temperature between a temperature corresponding to the maximum value and the Curie temperature,
wherein the mutual inductance measurement is configured to provide a remote measurement of the internal temperature of the device local to the thermomagnetic probe according to a predetermined relationship between the temperature-dependent magnetic permeability and temperature.

2. The thermomagnetic sensor of claim 1 , wherein the mutual inductance measurement employs an alternating magnetic field having a frequency between about 10 hertz and about 10 kilohertz.

3. The thermomagnetic sensor of claim 1 , wherein the plurality of coils is spatially arranged to externally surround the device such that the thermomagnetic probe is between the selected pair of coils of the plurality of coils without direct contact to the selected pair of coils.

4. The thermomagnetic sensor of claim 1 , wherein the plurality of coils is spatially arranged in a ring around the device to externally surround the thermomagnetic probe, an angular spacing between the coils around the ring being substantially equiangular.

5. The thermomagnetic sensor of claim 1 , wherein the coils of the selected pair are stationary, one or both of the device and the thermomagnetic probe inside the device being configured to be mobile with respect to the stationary coils.

6. The thermomagnetic sensor of claim 5 , further comprising a rotating member, the thermomagnetic probe being located on the rotating member, the stationary coils of the selected pair being arranged such that the thermomagnetic probe rotates between the stationary coils.

7. The thermomagnetic sensor of claim 1 , wherein the ferromagnetic material of the thermomagnetic probe comprises nickel.

8. The thermomagnetic sensor of claim 1 , wherein the thermomagnetic probe comprises the ferromagnetic material formed into one or more of a thin film, a plurality of particles, a spheroid, a wire and a rod.

9. The thermomagnetic sensor of claim 1 , wherein the thermomagnetic probe comprises a plurality of separate, spaced-apart sub-probes arranged inside the device, each sub-probe exhibiting a temperature-dependent magnetic permeability associated with a local temperature in a vicinity of the sub-probe,
wherein the plurality of coils is spatially arranged to externally surround the device such that each sub-probe is between a selected pair of coils of the plurality of coils, and
wherein mutual inductance measurements between different selected pairs of coils and sub-probes are configured to provide local temperatures in the vicinities of the sub-probes, a combination of the local temperatures being a multi-dimensional thermal image of the internal temperature of the device.

10. A battery-temperature measurement system comprising the thermomagnetic sensor of claim 1 , wherein the thermomagnetic probe is located inside a battery, the measurement of local temperature providing a remote measurement of an internal temperature of the battery.

11. The battery-temperature measurement system of claim 10 , wherein the thermomagnetic probe inside the battery is one or more of located in a current collector, a conducting agent, and a separator of the battery.

12. A battery-temperature measurement system comprising:
a thermomagnetic probe in a battery, the thermomagnetic probe comprising a ferromagnetic material having a temperature-dependent magnetic permeability that decreases monotonically as a function of temperature between a maximum value at a temperature below a Curie temperature of the ferromagnetic material and the Curie temperature;
a plurality of magnetic field coils external to the battery; and
a temperature measurement apparatus to determine a temperature of the battery according to a predetermined relationship between the temperature-dependent magnetic permeability and temperature using a mutual inductance measurement between selected magnetic field coils of the plurality to measure the temperature-dependent magnetic permeability,
wherein the determined temperature is between a temperature corresponding to the maximum value and the Curie temperature.

13. The battery-temperature measurement system of claim 12 , wherein the temperature measurement apparatus comprises an inductance meter to measure the mutual inductance of the selected magnetic field coils to determine the temperature-dependent magnetic permeability.

14. The battery-temperature measurement system of claim 12 , wherein the thermomagnetic probe comprises a plurality of separate, spaced-apart sub-probes, each sub-probe producing a temperature-dependent magnetic permeability associated with a local temperature in a vicinity of the sub-probe, and wherein a plurality of different measurements of the temperature-dependent magnetic permeability of the sub-probes in combination provides a multi-dimensional thermal image of the local temperature.

15. The battery-temperature measurement system of claim 12 , wherein the ferromagnetic material of the thermomagnetic probe comprises nickel, and wherein an alternating magnetic field of the temperature measurement apparatus has a frequency less than about 10 kilohertz.

16. A method of measuring temperature using a thermomagnetic effect, the method comprising:
locating a thermomagnetic probe and a plurality of coils with respect to a device in which an internal temperature of the device is to be remotely measured, the plurality of coils being spaced apart from one another external to the device and configured to provide a mutual inductance measurement between a pair of the coils of the plurality, the thermomagnetic probe being internal to the device physically spaced apart from and adjacent to the plurality of coils, the thermomagnetic probe comprising a ferromagnetic material having a temperature-dependent magnetic permeability characterized by a maximum value at a temperature below a Curie temperature of the ferromagnetic material, the temperature-dependent magnetic permeability monotonically decreasing between the temperature corresponding to the maximum value and the Curie temperature;
measuring a mutual inductance between a pair of the coils of the plurality to remotely determine the temperature-dependent magnetic permeability of the ferromagnetic material of the thermomagnetic probe; and
determining a temperature local to the thermomagnetic probe according to a predetermined relationship between the remotely determined temperature-dependent magnetic permeability and temperature, the determined local temperature being the local internal temperature of the device,
wherein the local internal temperature of the device is determined in a temperature range between the temperature corresponding to the maximum value and the Curie t

Assignees

• Hrl Lab Llc

Inventors

• Chang Chia-Ming
• Wang John
• Mcknight Geoffrey P
• Liu Ping

Classifications

• G01R31/3627

  Physics · mapped topic

• G01K7/36 Primary

  using magnetic elements, e.g. magnets, coils (magnetic elements per se H01F) · CPC title

• G01K7/38 Primary

  the variations of temperature influencing the magnetic permeability · CPC title

• G01K13/08

  in rotary movement · CPC title