Torsional Measurements Using an Optical non Contact Method

A method to determine torsional deflection of a turbine shaft, comprising:

• disposing at least two reflective/absorptive targets comprising a plurality of markings in a geometric pattern on the component;
• focusing a light emitting source onto a predetermined starting position on each of the targets;
• traversing the plurality of markings across the light emitting source;
• recording light pulses absorbed from the plurality of markings;
• and
• determining the torsional deflection of the component from the timing of the recorded light pulses from each of the targets;
• wherein the at least two targets are disposed in different axial positions along the component, and
• wherein the geometric pattern comprises at least two non-parallel lines and a third line including the predetermined starting position.

A system for determining a characteristic of a component on a turbine shaft, comprising:

• a component on the turbine shaft;
• a target including a plurality of markings in a geometric pattern disposed on the component;
• a light emitting source focused on a predetermined starting position on the target and configured to pass linearly over the plurality of markings from the predetermined starting position to obtain spatial data corresponding to the plurality of markings;
• a detector to receive and record light pulses reflected from/absorbed by the target;
• a processor configured to determine a characteristic of the turbine shaft from the received light pulses,
• wherein the geometric pattern comprises at least two non-parallel lines and a line including the predetermined starting position.