The influence of vibration transducer mounting on the practical measurement of railway vibration

When assessing ground-borne vibration related to railways, careful consideration needs to be given to the mounting and coupling of the transducers. This paper presents the results of research investigating some of these fundamental issues. Different couplant materials and four of the most commonly used transducer-to-ground coupling techniques (spikes, buried, slabs, and the transducer directly plastered to the ground), were compared and analysed within the frequency range 5 Hz to 500 Hz. The data demonstrate that transducer vertical alignment has limited influence at small angles. “Blu-tack” showed to be an adequate couplant. Above 50 Hz coupling systems can influence the reading by up to 20 dB. Using the train as a source of vibration yields a high degree of non-linearity on the coupling systems performance.