Optical gas temperature sensor

Patent metadata

Field	Value
Publication number	US-9506807-B2
Application number	US-201414221020-A
Country	US
Kind code	B2
Filing date	Mar 20, 2014
Priority date	Mar 21, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A thermometer comprises an emitting unit, a light receiving unit, a light collecting unit, and a calculation unit. The emitting unit is configured to emit a measurement light into a flue, wherethrough a gas that contains light scattering particles flows. The light receiving unit is configured to receive, of the measurement light, scattered measurement light scattered by the light scattering particles. The light collecting unit is configured to collect the scattered measurement light existing on the light receiving axis. The calculation unit is configured to calculate the temperature inside the flue based on an intensity ratio of absorption spectra at a plurality of wavelengths.

First claim

What is claimed is:

1. A thermometer, comprising:
an emitting unit configured to emit a measurement light along a measurement light axis into a flue, wherethrough a gas that contains light scattering particles flows, wherein the measurement light axis is formed between the emitting unit and the flue;
a light receiving unit configured to receive, of the measurement light, scattered measurement light scattered by the light scattering particles, wherein a wavelength of the emitted measurement light is the same as a wavelength of scattered measurement light after scattering by the light scattering particles;
a light collecting unit provided on a side closer to the flue than the light receiving unit, existing along a light receiving axis, and configured to collect the scattered measurement light existing on the light receiving axis, the light receiving axis extending between the light receiving unit and the prescribed position inside the flue, wherein either the light receiving axis and the measurement light axis coincide at least inside the flue, or the light receiving axis and the measurement light axis are formed at a first prescribed angle and a second prescribed angle, respectively, the first prescribed angle and the second prescribed angle being angles relative to an axis perpendicular to an extending direction of the flue, and the second prescribed angle being different from the first prescribed angle; and
a calculation unit configured to calculate the temperature inside the flue based on an intensity ratio of absorption spectra at a plurality of wavelengths, wherein the absorption spectra at the plurality of wavelengths are selected among absorption spectra of a prescribed component in the gas and included in the scattered measurement light received by the light receiving unit.

2. The thermometer according to claim 1 , wherein the absorption spectra are obtained by scanning the scattered measurement light at wavelengths in a prescribed wavelength band.

3. The thermometer according to claim 1 , wherein the emitting unit and the light receiving unit are provided such that the light receiving axis and a measurement light axis coincide at least inside the flue, the measurement light axis being an optical path of the measurement light.

4. The thermometer according to claim 1 , wherein the emitting unit and the light receiving unit are provided inside a same casing.

5. The thermometer according to claim 1 , further comprising an adjustment unit configured to adjust a center position of the light collecting unit.

6. A thermometer, comprising:
an emitting unit configured to emit a measurement light along a measurement light axis into a flue, wherethrough a gas that contains light scattering particles flows, wherein the measurement light axis is formed between the emitting unit and the flue;
a light receiving unit configured to receive, of the measurement light, scattered measurement light scattered by the light scattering particles along a light receiving axis, wherein a wavelength of the emitted measurement light is the same as a wavelength of scattered measurement light after scattering by the light scattering particles, and wherein either the light receiving axis and the measurement light axis coincide at least inside the flue, or the light receiving axis and the measurement light axis are formed at a first prescribed angle and a second prescribed angle, respectively, the first prescribed angle and the second prescribed angle being angles relative to an axis perpendicular to an extending direction of the flue, and the second prescribed angle being different from the first prescribed angle; and
a calculation unit configured to calculate the temperature inside the flue based on an intensity ratio of absorption spectra at a plurality of wavelengths, wherein the absorption spectra at the plurality of wavelengths are selected among absorption spectra of a prescribed component in the gas and included in the scattered measurement light received by the light receiving unit.

Assignees

• Horiba Ltd

Inventors

• Ido Takuya
• Mori Tatsuya

Classifications

• G01J5/0896

  using a light source, e.g. for illuminating a surface · CPC title

• G01J5/0806 Primary

  Focusing or collimating elements, e.g. lenses or concave mirrors · CPC title

• G01J5/042

  High-temperature environment (G01J5/0007, G01J5/0044, G01J5/0088 and G01J5/004 take precedence) · CPC title

• G01J5/084

  Adjustable or slidable · CPC title

• G01J5/0014

  for sensing the radiation from gases, flames · CPC title