Temperature sensors
A temperature sensor according to the disclosure herein includes an optical fiber structured to produce a thermal emission representative of a molten steel into which the temperature sensor is inserted; a cladding layer covering at least a portion of the optical fiber; and a spectrometer configured to receive the thermal emission from the optical fiber and to generate, in response, a radiation spectrum indicative of a temperature of the molten steel.
1 . A temperature sensor comprising:
an optical fiber structured to produce a thermal emission representative of a molten steel into which the temperature sensor is inserted;
a cladding layer covering at least a portion of the optical fiber;
a refractory housing covering at least a portion of the cladding layer, wherein the refractory housing includes at least two layers of increasing thickness arranged from an inner layer closest to the optical fiber to an outer layer; and
a spectrometer configured to receive the thermal emission from the optical fiber and to generate, in response, a radiation spectrum indicative of a temperature of the molten steel.
2 . The temperature sensor of claim 1 , wherein the cladding layer is nanoporous.
3 . The temperature sensor of claim 1 , wherein the cladding layer comprises a refractory material.
4 . The temperature sensor of claim 3 , wherein the refractory material is a ceramic material.
5 . The temperature sensor of claim 4 , wherein the ceramic material is selected from the group consisting of: SiO 2 , TiO 2 , ZnO 2 , and ZrO 2 .
6 . The temperature sensor of claim 1 , further comprising an air gap between an end of the optical fiber and an end of the cladding layer, wherein the air gap surrounds the cladding layer and separates the cladding layer from the refractory housing.
7 . The temperature sensor of claim 1 , wherein a refractive index of the optical fiber is less than a refractive index of the cladding layer.
8 . The temperature sensor of claim 1 , wherein the cladding layer comprises a thickness of at least 2 micrometers.
9 . The temperature sensor of claim 1 , wherein the cladding layer comprises a porosity of at least 25% of a total volume of the cladding layer.
10 . The temperature sensor of claim 1 , wherein the optical fiber is configured to collect a plurality of readings of a temperature of molten steel over a period of time.
11 . The temperature sensor of claim 10 , wherein the temperature of the molten steel is 1540° C. to 1750° C.
12 . The temperature sensor of claim 10 , wherein the period of time is at least 10 minutes.
13 . A temperature sensor comprising:
a sapphire optical fiber structured to produce a thermal emission in response to exposure to a heated material;
a spectrometer coupled to the sapphire optical fiber and configured to generate a radiation spectrum based on the thermal emission;
a cladding layer proximate the optical fiber, the cladding layer comprising a nanoporous material; and
a multi-layered refractory housing covering at least a portion of the cladding layer.
14 . The temperature sensor of claim 13 , wherein the heated material is molten steel, and a temperature of the molten steel is indicated by the radiation spectrum.
15 . The temperature sensor of claim 14 , wherein the temperature of the heated material is at least 1540° C.
16 . The temperature sensor of claim 14 , wherein temperature sensor is capable of exposure to the heated material for a period of at least 10 minutes.
17 . The temperature sensor of claim 13 , wherein the cladding layer comprises a refractory material.
18 . The temperature sensor of claim 17 , wherein the refractory material is a ceramic material.
19 . The temperature sensor of claim 13 , wherein an air gap surrounds a distal end of the cladding layer, the air gap separating the distal end the cladding layer from a distal end of the refractory housing.
20 . A temperature sensor comprising:
an optical fiber structured to produce a thermal emission representative of a heated material into which the temperature sensor is inserted;
a nanoporous layer covering at least a portion of the optical fiber;
a multi-layered refractory housing covering at least a portion of the nanoporous layer; and
a spectrometer configured to receive the thermal emission from the optical fiber and to generate, in response, a radiation spectrum indicative of a temperature of the heated material.
21 . The temperature sensor of claim 20 , wherein the temperature sensor is capable of exposure to the heated material for a period of at least 10 minutes and at a temperature of 1900° C.
22 . The temperature sensor of claim 20 , further comprising an air gap fully-circumferentially around the nanoporous layer, the air gap separating the nanoporous layer from the refractory housing.