An unusually high peak in a sensor signal does not necessarily originate from the machine itself. During measurements on a pump motor, the sensor showed an unexpectedly high response at 71.52 Hz, the first harmonic of the 35.52 Hz fundamental frequency. WaveCam’s full-field analysis revealed that an unsecured sensor cable was vibrating strongly at the same frequency and causing the anomalous peak.
To identify the source, the accelerometer signal was compared with optical measurements taken next to the sensor and directly on the cable. At 71.52 Hz, the motor housing showed only minor motion, while a strong response was visible in the sensor signal. The WaveCam animation confirmed that the vibration originated from the cable.
This case illustrates how full-field optical analysis and conventional sensors can complement and cross-validate each other. By capturing the entire visible area, WaveCam can reveal influences from the measurement setup that cannot be clearly identified from a single sensor signal. This helps distinguish measurement artifacts from actual machine vibration.
Our ICSV 32 paper presents further results from smartphone-based vibration measurements on machinery in power plants, including a comparison between WaveCam analysis and conventional accelerometers. It also provides more details on the measurement setup and data evaluation.
