Sensor, strain sensor, and pressure sensor

• US 9,891,119 B2
• Filed: 09/01/2015
• Issued: 02/13/2018
• Est. Priority Date: 09/04/2014
• Status: Active Grant

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Samejima, Takeru, Hamamatsu, Nobuyuki, Yoshida, Takashi
• Primary Examiner(s): Noori, Max
• Application Number:
  US14/842,273
• Publication Number:
  US 20160069755A1
• Time in Patent Office: 896 Days
• Field of Search: 73760, 73777, 73856
• CPC Class Codes: G01D 11/30 Supports specially adapted for an instrument; Supports specially adapted for a set of instruments
• CPC Class Codes: G01L 1/18 using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
• CPC Class Codes: G01L 1/26 Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 19/04 Means for compensating for effects of changes of temperature , i.e. other than electric compensation

Abstract

A sensor includes a first structure that is attachable to a measurement specimen, a second structure that is made of material which is smaller in thermal expansion coefficient than the first structure, a bottom surface of the second structure being connected to the first structure, and a detector that is connected to an upper surface of the second structure, the detector being configured to detect a deformation of the second structure.

Claims

1. A strain sensor comprising:

a first structure that is attached to a measurement specimen;

a second structure that is made of material which is smaller in thermal expansion coefficient than the first structure, a bottom surface of the second structure being annularly connected to the first structure; and

a strain detector that is connected to an upper surface of the second structure, the strain detector being configured to detect a strain of the second structure,

wherein the strain detector is configured to detect a strain in accordance with a stress acting on the measurement specimen.

2. The strain sensor according to claim 1,

wherein the strain detector is further configured to measure strains of the second structure in directions perpendicular to each other;

and

wherein a shape of the second structure is configured such that a strain of an outer end part of the second structure is zero.

3. The strain sensor according to claim 1, wherein

the second structure has a space, and

the second structure is any one of a columnar shape, a rectangular columnar shape, a truncated cone shape, and a truncated pyramid shape.

4. The strain sensor according to claim 1, wherein

a connection between the bottom surface of the second structure and the first structure is joined by any one of brazing, inorganic adhesive, glass frit bonding, SOG (Spin On Glass) wafer bonding, and welding.

5. The strain sensor according to claim 1, wherein

a connection between the upper surface of the second structure and the strain detector is joined by any one of inorganic adhesive, glass frit bonding, SOG wafer bonding, anodic bonding, metal diffusion bonding, and surface activated room temperature bonding.

6. The strain sensor according to claim 1, wherein

only a part of the upper surface of the second structure is connected to the strain detector.

7. The strain sensor according to claim 1, wherein

the first structure has a thermal expansion coefficient equivalent to a thermal expansion coefficient of the measurement specimen.

8. The strain sensor according to claim 6, wherein

whole of a bottom surface of the first structure is joined to the measurement specimen.

9. The strain sensor according to claim 6, wherein

the first structure comprises a foot part disposed on a surface facing the measurement specimen, and

the foot part and the measurement specimen are joined.

10. The strain sensor according to claim 1, wherein

the strain detector comprises one of a semiconductor strain gauge and a resonant strain gauge.

11. The strain sensor according to claim 3, wherein

any one of the first structure, the second structure, and strain detector has a through hole communicating to the space of the second structure.

12. The strain sensor according to claim 1, wherein

a width of the bottom surface of the second structure connected to the first structure and a width of the upper surface of the second structure connected to the strain detector are different from each other.

13. The strain sensor according to claim 1, wherein

the first structure is a substrate attached to the measurement specimen, and

the second structure is an intermediate structure disposed between the first structure and the strain detector.

14. The strain sensor according to claim 1, wherein the strain detector comprises two strain gauges configured to measure strains of the second structure, wherein the strain gauges measure strains of the second structure in directions perpendicular to each other.

15. The strain sensor according to claim 14, wherein the two strain gauges can be resonant strain gauges, semiconductor strain gauges, or a resonant strain gauge and a semiconductor strain gauge.

16. The strain sensor according to claim 1, wherein the strain detector is further configured to detect a strain of an end part of the second structure.

17. The strain sensor according to claim 16, wherein the strain of the end part being generated by the strain of the measurement specimen.

18. The strain sensor according to claim 1, wherein a shape of the second structure is configured such that a strain of an outer end part of the second structure is zero.