Abstract: An exploratory experiment is carried out on a turbo-shaft engine to study the relationship between the gas path electrostatic characteristics and the working conditions of the engine. Based on the signals monitored over a period of 108 h, several parameters are obtained and discussed, such as the activity level (AL), positive event rate (PER), negative event rate (NER) and shaft order analysis (SOA) of the engine. The results show that for a relatively healthy turbo-shaft engine: the feasibility of the technology is proved. The engine's working power clearly affects the amplitude of the induced signal, which becomes greater when the working condition changes from low to higher power. In the process of power change from low to high, AL varies in a quadratic polynomial trend while PER/NER change in a linear trend. As the experiment is unfolding, AL significantly increases under each power condition but PER/NER are almost constart. AL is greatly affected by engine washing but PER/NER are not.

Key words: turbo-shaft engine, exhaust gas, electrostatics, monitoring, engine washing