Monitoring apparatus for rotating machinery.

摘要

Monitoring apparatus for determining the condition of rotating machinery comprises an automatic gain control circuit (4) and digitally controlled filter (6) for conditioning an incoming signal into a plurality of frequency bands. Each band is selectively coupled to a non-linear filter (10) comprising an amplifier with a predetermined slew rate providing a high pass output (12) comprising signals of an impulsive nature and a low pass output (14) comprising periodic and rotational components of the incoming signal. A comparative threshold is derived from the low pass output in a digitally controlled comparator (16) in order to quantify the impulsive signals. A counter correlator (18) determines the number of impulsive signals arising within a predetermined time period and the periodicity of the incoming signals.