Patent ID: 8161806

Claim:
A method of monitoring engine performance parameters of a gas turbine engine while operating, the method comprising: mounting sensors on the engine to sense the engine performance parameters and generate analog sensor outputs; conditioning the analog sensor outputs to produce corresponding digital data, the conditioning step being performed with a control circuit board and at least one signal conditioning circuit board of at least one hub unit that is mounted sufficiently close to the engine so as to be subjected to a first temperature in excess of 125° C., the control circuit board and the signal conditioning circuit board comprising electrical circuit components that define an analog signal processing path and have accuracy and precision characteristics that drift in response to component aging and to changes in the first temperature to which the hub unit is subjected; receiving the digital data from the hub unit with a collector unit mounted sufficiently close to the engine so as to be subjected to a second temperature of less than the first temperature, the collector unit comprising an enclosure containing a system voltage reference device and means for maintaining the system voltage reference device at a regulated temperature; operating the system voltage reference device to produce a reference voltage; performing a continuous calibration scheme by periodically applying the reference voltage and a zero voltage to the signal conditioning circuit board to determine and remove errors in the analog signal processing path resulting from the drifts of the electrical circuit components of the control circuit board and the signal conditioning circuit board; and receiving the digital data from the collector unit with a distributor computer unit located sufficiently remote from the engine so as to be subjected to a third temperature of less than the second temperature, the distributor computer unit processing the digital data to assess the engine performance parameters of the engine.