Temperature sensor and method of manufacture
The temperature sensor can have a core having a length extending between two ends, the core having a cavity extending along the length, a wire extending in the cavity, along the length, the wire fixed at both ends, the core having a transversal aperture at an intermediary location between the ends, the transversal aperture leading into the cavity, and a potting filling a portion of the cavity and supporting the wire at the intermediary location of the transversal aperture.
1. A temperature sensor comprising a core having a length extending between a first end and a second end, the core having a cavity extending along the length, a wire extending in the cavity, along the length, the wire fixed at the first end and at the second end, the core having a transversal aperture at an intermediary location between the ends, the transversal aperture leading into the cavity, and a potting filling a portion of the cavity and supporting the wire at the intermediary location of the transversal aperture.
2. The temperature sensor of claim 1 , further comprising at least two unsupported portions of the wire, each between the potting and a corresponding end, the length of each unsupported portion of the wire being smaller than a length of the wire between the two ends.
3. The temperature sensor of claim 1 further comprising at least two of said transversal apertures and pottings, the transversal apertures and pottings being interspaced along the length of the core and supporting the wire at respective intermediary locations between the ends.
4. The temperature sensor of claim 1 wherein the diameter of the wire is of between 0.005″ and 0.020″.
5. The temperature sensor of claim 4 wherein the core is cylindrical and the cavity has a diameter of less than 3 times the diameter of the wire.
6. The temperature sensor of claim 1 wherein the core is cylindrical and the cavity has a diameter of less than 3 times the diameter of the wire.
7. The temperature sensor of claim 1 wherein the core is made of an electrically insulating material.
8. The temperature sensor of claim 1 wherein the wire is fixed at both ends by corresponding pottings.
9. The temperature sensor of claim 1 wherein the wire is made of platinum.
10. The temperature sensor of claim 1 wherein a sensing coil is wrapped around the core, the sensing coil is made of a material having a diameter smaller than the diameter of the wire, the sensing coil being electrically connected to the wire at a distal one of the ends.
11. The temperature sensor of claim 10 further comprising a first electrical lead connected to the wire at a proximal one of the ends, and a second electrical lead connected to the sensing coil at the proximal end, a base supporting the coil, and a metal shell secured to the base and covering the core and the sensing coil, an electrical power source for inducing current circulation along the sensing coil via the leads, and a meter for measuring a response of the sensing coil to the induced current circulation.
12. A method of making a temperature sensor, the method comprising:
introducing material into a gap between a wire of the sensor and an inner wall of a core of the sensor, via a transversal aperture in the core;
said material holding a portion of the wire relative to the core thereafter; and
wrapping a sensing coil around the core, and connecting one end of the sensing coil to a corresponding end of the wire.
13. The method of claim 12 wherein said material is potting material initially introduced in malleable form and subsequently solidified.
14. The method of claim 13 further comprising introducing said potting material, in malleable form, into the gap between the wire and the inner wall of the core, via the ends of the core, and solidifying the potting material introduced via the ends of the core.
15. The method of claim 14 wherein the step of introducing potting material via the transversal aperture is performed subsequently to the step of introducing potting material via the ends, and the holding of the wire relative to the core increases the natural frequency of unsupported portions of the wire compared to the natural frequency of the wire prior to introducing the potting material via the transversal aperture.
16. The method of claim 12 further comprising inducing current circulation along an electrical circuit including the wire, and measuring a response of the electrical circuit to the induced current circulation.
17. The method of claim 14 wherein said introducing potting material includes said potting material being prevented from penetrating further along the gap due to the size of the gap and the nature of the potting material, thereby leaving unsupported portions of the wire on both sides.
18. A gas turbine engine comprising a temperature sensor, the temperature sensor comprising a core having a length extending between two ends, the core having a cavity extending along the length, a wire extending in the cavity, along the length, the wire fixed at both ends, the core having a transversal aperture at an intermediary location between the ends, the transversal aperture leading into the cavity, and a potting filling a portion of the cavity and supporting the wire at the intermediary location of the transversal aperture.
19. The gas turbine engine of claim 18 wherein the gas turbine engine is a turboprop or turboshaft engine.