Digital Data Acquisition System for Use in Aircraft Engine Condition Monitoring,

A digital data acquisition system is described which has been developed as part of a project to investigate assessment of aircraft engine condition from in-flight recording of a number of parameters. The recording system is based on a small inexpensive audio tape recorder, and accepts up to 12 analogue inputs and 4 digital inputs. Recording of data in digital form is made on a standard cassette using a novel frequency coding technique. Other novel aspects of the system are the successful application of a computer-like architecture to an essentially simple system and the ease with which data can be displayed for calibration and pre-flight checks with simple hand held test gear. Author