Abstract:
A method of zeroing displacement data derived from a rotor having an array of features monitored by an array of stationary timing probes. The method includes steps to calculate the displacement at each probe for each of at least two measured revolutions from time of arrival measurements. Each displacement is defined as a sum of a common term and a unique term. The set of displacements is solved for the common term and the unique terms. A probe offset is calculated from each unique term. The zeroed displacements are determined by subtracting the common term and probe offset from the calculated displacements for each probe.
Abstract:
A boroscope (60) has a first end (62) and a second end (64) and the first end (62) of the boroscope (60) has an optical fibre (66) and light source (68). A working head (70) is attached to the first end (62) of the boroscope (60). The working head (70) has an electrical motor (72) and a tool (74) is attached to and is arranged to be driven by the electrical motor (72) and the boroscope (60) carries a cable (76) extending from the electrical motor (72) to the second end (64) of the boroscope (60).
Abstract:
A method of providing a time reference for a rotor, for example a once per revolution time reference. The rotor includes N time of arrival features. The method includes steps for each revolution of the rotor. Provide a plurality of time of arrival probes spaced apart circumferentially outside the periphery of the rotor and measure a time of arrival of each feature at each probe. Select N time of arrival measurements at each probe. Derive a best fit of the measured times of arrival measured at all the probes against angular position. Set the time reference for the next revolution of the rotor equal to the best fit at the end of the current revolution of the rotor. Also a rotor arrangement for the method.