TEMPERATURE SENSOR USING THIN FILM RESISTANCE TEMPERATURE DETECTOR
The present subject matter relates generally to temperature sensors using a thin film element. Various embodiments of the present subject matter include a temperature sensor assembly. The temperature sensor assembly includes an enclosure having an inside surface and a thin film element housed in the enclosure. A thermally conductive material connects a surface of the thin film element directly to the inside surface of the enclosure in a side mounted manner to provide rapid thermal conduction from the enclosure to the thin film element. In various embodiments, the thin film element is a resistance temperature detector (RTD).
1 . A temperature sensor assembly, comprising:
an enclosure having an inside surface; and
a thin film element housed in the enclosure, wherein a thermally conductive material connects a surface of the thin film element directly to the inside surface of the enclosure in a side mounted manner to provide rapid thermal conduction from the enclosure to the thin film element.
2 . The assembly of claim 1 , wherein the enclosure includes a metal enclosure.
3 . The assembly of claim 1 , wherein the enclosure includes a cylindrical enclosure.
4 . The assembly of claim 1 , wherein the thin film element includes a thin film resistance temperature detector (RTD).
5 . The assembly of claim 1 , wherein the thermally conductive material includes a thermally conductive adhesive.
6 . The assembly of claim 5 , wherein the thermally conductive adhesive includes a silicone adhesive.
7 . The assembly of claim 5 , wherein the thermally conductive adhesive includes an epoxy adhesive.
8 . The assembly of claim 1 , wherein the surface of the thin film element is completely covered by the thermally conductive material.
9 . The assembly of claim 1 , wherein the surface of the thin film element is rectangular in shape and has dimensions ranging from approximately 1 mm by 1 mm to approximately 5 mm by 5 mm.
10 . The assembly of claim 1 , wherein the thermally conductive material includes solder.
11 . The assembly of claim 1 , wherein the thermally conductive material is selected to provide thermal transfer from the enclosure to the thin film element at a desired rate.
12 . The assembly of claim 1 , wherein the thin film element includes a substrate having a thin film patterned on a first side and a plated backing on a side opposite the first side, the plated backing adapted for mounting to the inside surface of the enclosure.
13 . The assembly of claim 1 , wherein the enclosure has a wall thickness of approximately 0.016 inches or less.
14 . The assembly of claim 1 , further comprising a plurality of thin film elements side mounted to the inside surface of the enclosure.
15 . The assembly of claim 14 , wherein the plurality of thin film elements includes thin film elements that are uniform in size.
16 . A method of making a temperature sensor assembly, the method comprising:
connecting a surface of a thin film resistance temperature detector (RTD) directly to the inside surface of a thin-walled cylindrical metal enclosure in a side mounted manner using a thermally conductive material to provide rapid thermal conduction from the enclosure to the RTD.
17 . The method of claim 16 , further comprising separating the thin film RTD from a distal end of the enclosure to provide thermal insulation to the thin film RTD.
18 . The method of claim 17 , comprising separating the thin film RTD by at least approximately 1/16 of an inch from the distal end of the enclosure proximal the thin film RTD.
19 . The method of claim 16 , further comprising connecting leads to the thin film RTD and connecting wires to the leads.
20 . The method of claim 16 , further comprising minimizing mass of the thin film RTD and surrounding structure to provide rapid thermal conduction from the metal enclosure to the thin film RTD.