1. Field of the Invention
The invention concerns an apparatus intended for continuously measuring the temperature of a flow of gas within a grid of blades constituted by a plurality of stationary blades disposed in a crankcase which delimits the flow. In particular, the invention contemplates an apparatus for measuring the temperature of gases within a turbojet turbine stage valve.
2. Description of the Prior Art
It is known that in jet-propelled aircraft, it is necessary to measure the temperature of the gases traversing the turbine and to display that temperature by means of gauges disposed on the control panel so that the pilot may be assured at all times that this temperature does not reach a dangerous level. The measurements are carried out by means of sounders or captors, generally thermocouples, connected to the gauges.
In engines having two turbine stages separated by an intermediate crankcase, sounders may be disposed within the crankcase. This solution is not possible in compact engines not having such a crankcase. The sounders may not be disposed between the outlet valve blades since in that position they would cause a considerable partial obstruction. In a known solution, the sounders may be integrated with the leading edges of certain stationary blades. However, it is difficult to effectively protect the sounder conductor links against thermal and chemical damage from the gases. This becomes more difficult as the number of conductors increases. In practice, it is necessary to dispose the sounders on several radii of the jet stream section so as to obtain a suitable measure of the average gas temperature within the section. By way of example, it is necessary to dispose six sounders in a 120 blade valve. At three conductors per sounder, there are then 18 wires which must be placed and protected against damage from ambient conditions.