摘要 |
To be of most use as an input signal for the control system of a gas turbine aeroengine, a pyrometer-derived turbine blade temperature signal should represent the average temperature of the hottest parts of the blades with fast and accurate response when the average temperature of the hottest parts changes with engine conditions. The invention achieves this by providing the pyrometer with an optical system adapted to give the pyrometer's photo-diode a large field of view which is rectangular at the face of the turbine rotor and which extends an integer number of inter-blade passage widths in the circumferential direction and a portion of the length of the blade aerofoils in the radial direction. The large rectangular field of view is achieved by masking the optical system and arranging that it cooperates with a small aperture in the wall of the turbine gas passage in such a way that at the aperture the field of view lies entirely within the boundary of the aperature, the field of view expanding out of the aperture to produce the required rectangular field of view at the face of the turbine rotor.
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