Recently, the maintenance team at a mill in north-west France shared with SDT an unusual but crucial piece of feedback on mechanical fault detection using ultrasound, highlighting how this method surpassed the capabilities of vibration analysis in accurately identifying the problem. 

This paper mill had a recurring problem with its filter. This filter, essential to their production process, had a problem with annoying noise and regular shocks to the agitator. This problem was seriously affecting their productivity and the quality of their final product.

One day, the team in question decided to solve this noisy mystery using the SDT340, a state-of-the-art ultrasound measurement device. They positioned it strategically to investigate the sources of this annoying noise. After careful ultrasound listening, they discovered something interesting: shocks at a frequency of 0.3 Hz on the GV/PV points, visible in the UAS3 software in the image below.