Pyrometers
AssigneeRosemount Aerospace Inc.
InventorTim Aadland
Life of this patent
Estimating the term…
Abstract
A pyrometer configured to sense thermal radiation within a volume (e.g., a turbomachine turbine or turbine engine) can include a photodiode configured to sense radiation at least within a desired infrared bandwidth and to output a photodiode signal, and an optical bandpass filter disposed in front of the photodiode to prevent radiation outside of the desired bandwidth from reaching the photodiode. The desired infrared bandwidth can be selected to be outside the absorption bands of one or more selected fluids such that the presence of one or more fluids (gasses) within the volume does not affect radiation that reaches the photodiode.
Claims20
A pyrometer configured to sense thermal radiation within a volume, comprising:
- a photodiode configured to sense radiation at least within a desired infrared bandwidth and to output a photodiode signal;
- and
- a bandpass filter disposed in front of the photodiode to prevent radiation outside of the desired bandwidth from reaching the photodiode, wherein the desired infrared bandwidth is selected to be outside the absorption band of one or more selected fluids such that the presence of one or more fluids within the volume does not affect radiation that reaches the photodiode, wherein the photodiode is doped to prevent a cutoff wavelength of the photodiode interacting with a transmittance curve of the bandpass filter such that any drift over temperature is outside of the transmittance curve of the bandpass filter.
A pyrometer configured to sense thermal radiation within a volume, comprising:
- a photodiode configured to sense radiation at least within a desired infrared bandwidth and to output a photodiode signal directly proportional to the sensed radiation;
- a bandpass filter disposed in front of the photodiode to prevent radiation outside of the desired bandwidth from reaching the photodiode, wherein the desired infrared bandwidth is selected to be outside the absorption band of one or more selected fluids, wherein the one or more selected fluids are at least carbon dioxide and H2O such that the presence of one or more fluids within the volume does not affect radiation that reaches the photodiode, wherein the photodiode is doped to prevent a cutoff wavelength of the photodiode interacting with a transmittance curve of the bandpass filter such that any drift over temperature is outside of the transmittance curve of the bandpass filter;
- and
- a chopper stabilized op amp operatively connected to the photodiode to receive the photodiode signals and configured to output one or more sensor signals.
A method, comprising:
- providing a pyrometer configured to sense thermal radiation within a volume, comprising:
- a photodiode configured to sense radiation at least within a desired infrared bandwidth and to output a photodiode signal;
- and
- a bandpass filter disposed in front of the photodiode to prevent radiation outside of the desired bandwidth from reaching the photodiode, wherein the desired infrared bandwidth is selected to be outside the absorption band of one or more selected fluids such that the presence of one or more fluids within the volume does not affect radiation that reaches the photodiode, wherein the photodiode is doped to prevent a cutoff wavelength of the photodiode interacting with a transmittance curve of the bandpass filter such that any drift over temperature is outside of the transmittance curve of the bandpass filter;
- sensing the radiation being emitted from a turbine blade of a turbine engine outside any bandwidths that correspond to any absorption bands of CO2 and H2O;
- and
- determining a turbine blade temperature based on the sensed radiation.
Dependencies are inferred from the claim text.