Probe for sensing and measuring temperature

• US 5,193,912 A
• Filed: 11/18/1991
• Issued: 03/16/1993
• Est. Priority Date: 11/18/1991
• Status: Expired due to Term

• Current Assignee: Electronic Controls Design, Inc.
• Original Assignee: Roger I. Saunders
• Inventors: Saunders, Roger I.
• Primary Examiner(s): YASICH, DANIEL
• Application Number:
  US07/793,197
• Time in Patent Office: 484 Days
• Field of Search: 374/179, 374/180, 374/208, 136/231, 136/232, 136/233
• US Class Current: 374/179
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations

Abstract

This is a method and apparatus for removably mounting a thermocouple in intimate thermal contact with an electrical component or other object whose temperature is to be accurately sensed and measured. The apparatus comprises a probe having a miniaturized "gripper" or a spring-biased sensor for perceiving the temperature at a precisely defined point. Provision is made for shielding the thermocouple from ambient gases that might degrade the desired temperature perception. Various provisions are made for removably mounting the shielded thermocouple on or in contact with a circuit board or an independent structure.

Claims

1. Probe apparatus for sensing the temperature of at least one electronic component positioned on the surface of a circuit board without causing appreciable relative motion between said component and said circuit board, said apparatus comprising:

(a) a thermocouple junction of dissimilar materials, said thermocouple junction having a protective sheath thereon,

(b) first and second electrical leads disposed axially inside said protective sheath and terminating at said thermocouple junction,

(c) tubular metallic means surrounding said protective sheath and said first and second electrical leads to a point substantially abreast of said thermocouple junction but spaced from said sheath and said junction,

(d) thermally-and-electrically-insulating means for rigidly maintaining the position of said junction substantially centered within and radially spaced from an end of said tubular metallic means substantially abreast of said junction to prevent relative motion between said thermocouple junction and said tubular metallic means in an axial or radial direction, and

(e) means for causing said protective sheath and said thermocouple junction to make good thermal contact with said component without displacing said component on said circuit board in a direction either normal to or parallel to said circuit board.

2. Apparatus in accordance with claim 1 in which said thermally-and-electrically-insulating means is sufficiently rigid substantially to prevent relative motion in a radial or axial direction between said junction and said tubular metallic means.

3. Apparatus in accordance with claim 1 in which said sheathed thermocouple junction, said thermally-and electrically-insulating means and said end of said tubular metallic means are combined to form a sensor tip of said apparatus.

4. Apparatus in accordance with claim 3 in which said thermocouple junction is electrically connected to its protective sheath.

5. Apparatus in accordance with claim 1 in which said device is an electronic component.

6. Apparatus in accordance with claim 1 in which said device is a localized temperature-sensitive portion of a circuit board assembly.

7. Probe apparatus for sensing the temperature of at least one electronic component positioned on the surface of a circuit board without causing appreciable relative motion between said component and said circuit board, said apparatus comprising:

(a) a thermocouple junction of dissimilar materials having a sheath for supporting and protecting said thermocouple junction against damage.

(b) first and second electrical leads terminating at said thermocouple junction,

(c) tubular metallic means surrounding said first and second electrical leads and said sheath to a point substantially abreast of said thermocouple junction but spaced from said leads and said junction,

(d) heat-resistant electrically-and-thermally-insulating means for rigidly maintaining the position of said junction substantially centered within and radially spaced from an end of said tubular metallic means substantially abreast thereof to prevent relative motion between said thermocouple junction and said tubular metallic means in an axial or radial direction thereof, and

(e) means for causing said sheath and said thermocouple junction to make good thermal contact with said component without displacing said component on said circuit board.

8. Apparatus in accordance with claim 7, further including body means surrounding a portion of said tubular metallic means, and support means for said body means, said body means having one end which is flared outwardly from said tubular metallic means so as to allow relative motion of said tubular metallic means in a first direction transverse to said body means while confining said tubular metallic means against substantial relative motion with respect to said body means in a direction normal to said first direction, to form an aperture for through passage of said tubular metallic means, said tubular metallic means being supported in cantilever fashion within said body means and having elasticity sufficient to resist but to allow deflection of said tubular metallic means within said aperture.

9. Apparatus in accordance with claim 8 wherein the unstressed position of said tubular metallic means when passing through said aperture of said body is at one end of said aperture.

10. Apparatus in accordance with claim 9 in which the position of said tubular metallic means when said apparatus is exerting operating mechanical force on said device is at or near the center of said aperture.

11. Apparatus in accordance with claim 8 in which said support means for said body means includes clamping means for removably attaching said support means to a portion of a circuit board or circuit-board support on which said device may be positioned.

12. Apparatus in accordance with claim 8 in which said support means includes means for adjusting the position of said body means with respect thereto.

13. Apparatus in accordance with claim 8, further including connector means mounted on said body means for coupling said first and second electrical leads to external control, indicating, or display instrumentation.

14. A method for measuring the temperature of a device such as an electronic component supported on a surface such as a circuit board substantially without displacing the position of said device with respect to said surface either perpendicularly or parallel to said surface, comprising the steps of:

(a) encasing a thermocouple junction in a protective covering,

(b) surrounding said protective covering with a metallic shield that is spaced from said protective covering and fixed to prevent relative motion between said thermocouple junction and said metallic shield,

(c) forming a sensor-tip assembly by providing an annular thermally-and-electrically-insulating spacer between said thermocouple junction and said metallic shield,

(d) bringing said sensor-tip assembly into contact and maintaining it in good thermal contact with said device whose temperature is to be measured, and

(e) reading the electrical output of said thermocouple junction while said good thermal contact is maintained.

15. A method in accordance with claim 14, including the additional step of displaying on or utilizing with a suitable instrument a representation of said electrical output of said thermocouple junction.

16. A method for measuring the temperature of a device such as an electronic component positioned on a supporting surface such as a circuit board substantially without altering the position of said device with respect to said supporting surface either perpendicularly or parallel to said supporting surface, comprising the steps of:

(a) encasing a temperature sensor in a protective covering,

(b) enclosing said protective covering, said temperature sensor, and the electrical leads of said temperature sensor in a metallic shield that is spaced from said protective covering and disposed to prevent relative motion between said metallic shield and said temperature sensor,

(c) forming a sensor-tip assembly by providing a thermally-and-electrically-insulating seal between said temperature sensor and its protective covering and said metallic shield,

(d) bringing said sensor-tip assembly into contact with and maintaining good thermal contact between it and said device whose temperature is to be measured, and

(e) deriving from said electrical leads of said temperature sensor a signal expressive of the temperature of said device.

17. Probe apparatus for sensing the temperature of a device such as an electronic component positioned on a supporting surface such as a circuit board substantially without altering the position of said device with respect to said supporting surface in any relative direction therebetween, said probe apparatus comprising:

(a) a thermocouple junction of dissimilar materials,

(b) first and second electrical leads terminating at said thermocouple junction,

(c) tubular metallic means surrounding said first and second electrical leads to a point substantially abreast of said thermocouple junction but spaced from said leads and said junction, said tubular metallic means being bent so as to have an outboard leg extending normal to said surface,

(d) heat-resistant electrically-and-thermally-insulating means for rigidly maintaining the position of said junction substantially centered within and radially spaced from an end of said tubular metallic means substantially abreast thereof to prevent relative motion between said thermocouple junction and said tubular metallic means in an axial or a radial direction thereof, and

(e) body means surrounding and supporting a portion of said tubular metallic means, said body means having one end which is flared outwardly from said tubular metallic means so as to allow relative motion of said tubular metallic means in a first direction transverse to said body means while confining said tubular metallic means against substantial relative motion with respect to said body means in a direction normal to said first direction, to form an aperture for through passage of said tubular metallic means, said tubular metallic means being supported in cantilever fashion within said body means and having elasticity sufficient to resist but to allow deflection of said tubular metallic means within said aperture.