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Cross Channel Phase
Phase analysis is an effective way to diagnose machine faults such as
misalignment, resonance, soft foot, and looseness. Phase analysis is also
useful for distinguishing faults that look like imbalance but are actually
caused by something else. For example, misalignment can show up at
1X RPM, similar to imbalance. Knowledge of the phase relationships of
various machine faults will help confirm the existence of a specific
machine fault and help prevent misdiagnosis.
Cross Channel Phase is a convenient method of taking phase
measurements. It does NOT require the use of a tachometer or reflective
tape. Instead, phase is measured between two sensors.
NOTE: When taking measurements, be aware of the direction each
sensor is facing. If you are measuring across the coupling in the
axial direction, you will probably turn the sensors in opposite
directions, thereby introducing an additional 180° phase change.
Remember to take this into consideration when analyzing the
phase measurements.
Section 4 — Measurement Types and their Uses
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