Integrated environmental sensor for damage sensing

Patent metadata

Field	Value
Publication number	US-10955372-B2
Application number	US-201916380474-A
Country	US
Kind code	B2
Filing date	Apr 10, 2019
Priority date	Apr 10, 2019
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

An equipment-monitoring system having a resistive sensor designed for two- or four-terminal sensing of damage thereto caused by an environmental exposure. In an example embodiment, the resistive sensor comprises a sense resistor susceptible to the environmental exposure and a reference resistor protected from the environmental exposure, the sense and reference resistors being internally connected to four terminals of the sensor in a manner that enables external bridge-type measurements of the electrical resistance of the sense resistor. In some embodiments, the sense resistor comprises a relatively large number of flat metal stripes connected in parallel to one another between two of the four terminals, which advantageously provides an extended dynamic range of the damage detectable with the corresponding sensor and improves the sensor reliability. In various embodiments, the disclosed resistive sensors can be used to monitor damage to electrical circuits and/or critical structural elements of the corresponding equipment.

First claim

What is claimed is:

1. An apparatus comprising:
a control circuit; and
an integrated planar resistive sensor having a first parallel array of electrically conductive traces electrically connected across electrical terminals of the control circuit, the first parallel array being constructed to expose at least some of the electrically conductive traces thereof to an environmental atmosphere; and
wherein the control circuit is configured to generate an alarm in response to measuring a resistance of the integrated planar resistive sensor that is higher than a threshold, the threshold being such that the alarm is not automatically generated in response to only one of the electrically conductive traces being broken.

2. The apparatus of claim 1 , wherein at least some of the electrically conductive traces have a serpentine shape.

3. The apparatus of claim 1 , wherein the first parallel array has at least three electrically conductive traces.

4. The apparatus of claim 1 , wherein the first parallel array has at least ten electrically conductive traces.

5. The apparatus of claim 1 , wherein the threshold is such that the alarm is not automatically generated in response to two of the electrically conductive traces being broken.

6. The apparatus of claim 1 , wherein the threshold being such that the alarm is not automatically generated in response to three of the electrically conductive traces being broken.

7. The apparatus of claim 1 , further comprising a second parallel array of electrically conductive traces electrically connected across electrical terminals of the control circuit, at least some of the electrically conductive traces of the second parallel array being isolated from the environmental atmosphere by one or more protective layers.

8. The apparatus of claim 7 , wherein the control circuit is configured to compare electrical resistances of the first and second parallel arrays.

9. The apparatus of claim 7 , wherein the first and second parallel arrays have a same number of electrically conductive traces.

10. The apparatus of claim 7 , wherein the control circuit is configured to measure electrical resistance of the first parallel array using a bridge circuit, the bridge circuit having the second parallel array connected therein as a reference resistor.

11. The apparatus of claim 7 ,
wherein the electrically conductive traces of the first parallel array are connected in parallel to one another between first and second ones of the electrical terminals; and
wherein the electrically conductive traces of the second parallel array are connected in parallel to one another between third and fourth ones of the electrical terminals.

12. The apparatus of claim 11 , wherein the integrated planar resistive sensor includes an electrically conductive trace connected between the first and second parallel arrays.

13. The apparatus of claim 11 ,
wherein the electrical resistance between the first and second ones of the four electrical terminals is in a range between 0.1Ω and 10Ω; and
wherein the electrical resistance between the third and fourth ones of the four electrical terminals is in the range between 0.1Ω and 10Ω.

14. The apparatus of claim 1 , wherein the integrated planar resistive sensor is attached to a structural element of an enclosure for electrical equipment, the enclosure hosting therein the control circuit.

15. The apparatus of claim 1 , wherein the first parallel array of electrically conductive traces in an undamaged state and the second parallel array of electrically conductive traces have a same electrical resistance.

16. The apparatus of claim 1 , wherein the control circuit is configured to set an alarm threshold based on a set of resistance values measured at different times.

Assignees

• Nokia Technologies Oy

Inventors

• Xu Chen

Classifications

• G01N27/045 Primary

  Circuits (measuring resistance per se G01R27/00, e.g. G01R27/22) · CPC title

• G01N17/04

  Corrosion probes · CPC title

• G01N27/20 Primary

  Investigating the presence of flaws · CPC title

• G01R1/203

  Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts (resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R) · CPC title