Miniature Temperature Probe

Recognizing a need for an improved device to measure high temperatures in fabrics and flexible thermal insulations, NASA Ames has developed a method and apparatus that is particularly well suited for sensing temperatures on the surface or within these materials. Temperature sensing in flexible insulation has in the past involved positioning a bare thermocouple element within the fabric or insulation. The unprotected element is destroyed by temperatures greater than 2700 degrees Fahrenheit in an oxidizing atmosphere and does not stay in position making it impossible to know the temperature at a fixed location. With the new temperature sensing device, it is now possible to measure temperatures at a range of 100 to 3200 degrees Fahrenheit in an oxidizing and aeroconductive environment without damage to the device or the temperature sensing wire. The new device can also be installed in a fixed position, thus determining the temperature in a known exact position. The sensor can be employed in any environment where it is desirable to measure high temperatures at precise locations. The apparatus uses a type R thermocouple wire element in a ceramic sheath to sense temperatures up to 3200 degrees Fahrenheit in any heating environment. The sheath has two sections disposed at right angles to each other. The junction of the thermocouple is located at one end of one of the sections and the lead wires extend from the other section. The section which includes the junction is secured to a flexible surface with ceramic cement. The wires lead to a mini-voltmeter and, if desired, a data recorder. Conversion software is available that converts voltage detected by the device to an actual temperature reading.

Potential Commercial Uses

• The temperature probe can be used to test thermal insulation materials.
  
• The probe can be used in automobiles to sense temperatures within catalytic converters, thus optimizing emission performance of engines.
  
• The miniature temperature probe could be used in the plastics industry to monitor curing temperatures and alert molding operators when temperatures exceed limits.
  
• The probe can be used within cast metals to determine temperatures at various locations.
  
• Probes could be installed throughout firewalls and other structures subject to extreme temperatures to monitor specific locations and activate alarms or alert personnel when temperatures reach prespecified levels.
  
• The sensor can be employed in any environment where it is desirable to measure high temperatures at precise fixed locations. The advantage of this probe is its miniature size, which allows it to be embedded without the need for removal.

Benefits

• Miniature: The miniature temperature probe is one inch in length and approximately the thickness of a mechanical pencil lead (.03 inch).
  
• Accurate: The device measures temperatures with an accuracy of ±1% at 3000 degrees Fahrenheit as demonstrated by a comparison of actual measurements with computer analytical modeling.
  
• Real-time measurement and data collection: Two thin wires emit from the probe relaying real-time data to a mini-voltmeter and data recorder that registers all incoming information. The voltage detected by the device can instantly be converted into an actual temperature reading by available conversion software.
  
• Easy installation: The probe can easily be installed into fabrics, insulations, composites, and thermoplastic, composite, or metal moldings without changing their configurations or affecting their performance. It can be mounted on the exterior using a high temperature resistant ceramic adhesive, or silicone adhesive for lower temperature applications.
  
• Easy to operate: Those familiar with high temperature measurement will find this probe easy to understand and operate. Even those not familiar with current temperature measurement techniques could use the probe with minimal training.
  
• Reusable or disposable: When mounted on the exterior, the probe can be removed and reused. When embedded into a material, the device is inexpensive enough to leave embedded.
  
• Low fabrication cost: The miniature temperature probe is easily and inexpensively fabricated, and future manufacturing of the probe could easily be automated with the development of appropriate tooling.

Options for Commercialization

The NASA Ames Research Center is currently seeking industrial partners to further develop applications for the Miniature Temperature Probe. This technology is described in U.S. Patent #5,399,019 issued to Demetrius A. Kourtides. Licensing options are available for the manufacture and distribution of this technology for specific and general applications.

Contact

NASA Ames Research Center
Commercial Technology Office
Mail Stop 202A-3
Moffett Field, CA 94035-1000
Tel: 650-604-0625

http://ctoserver.arc.nasa.gov:80/TechOpps/miniprob.html

Key Words

Transportation, Environmental, Advanced Materials, Medical Devices, Thermal Insulations, High Temperature Measurement, Miniature Temperature Probe