Human Generated Vibrations and Museum Exhibits
Last year the OUMP Innovation Fund supported a project called Quantifying and Mitigating Human Generated Vibrations to Museum Exhibits, led by the Ashmolean Museum Conservation Team in partnership with Engineering Science. Work was undertaken by Manolis Chatzis (Associate Professor) and Maria Espinosa (DPhil Candidate) in Engineering Science, and Daniel Bone (Deputy Head of Conservation) and Mark Norman (Head of Conservation) from the Ashmolean.
The focus of the project was to set up a sensor network to record the effect of vibrations, in particular those generated during musical events, on museum artefacts. By measuring the impact, the museum hopes to be able to look for mechanisms to mitigate effects on its displays.
The first stage of the project involved setting up the sensors, a wireless data acquisition system which became known as CDAQ, and develop the necessary algorithms for monitoring. The software, developed in LabView, allowed for : continuous recording of acceleration signals; detection of excedance of critical velocity with two levels of importance (minor and major); separate recording of signals related to events; and notifications. The software was a tailored modification of a tool developed by Smyth, Brewick, Greenbaum and Chatzis as described in an article in the Journal or the American Institute of Conservation.
The PC running the software was linked with the CDAQ initially via the Wi-Fi network. However, initial testing during a busy late night opening at the Ashmolean in October 2015 revealed technical issues as the volume of visitor mobile traffic on the network interfered with the connection. The team moved the CDAQ connection onto a dedicated network, but this also proved problematic as due case security the CDAQ had to be placed in the metal lower compartment of the case, which blocked Wi-Fi signals. Several solutions were explored, but eventually the PC had to be placed in the case alongside the CDAQ with a direct connection.
This new set up was tested at another late night event in May 2016 and worked well, recording continuously throughout the event and detecting several signifcant events.
Going forward the data collected by the system will be useful in understanding the correlation between music sources and vibrations of the artefacts. The data will be processed by Engineering Science with the aim of backing up theoretical findings, and the museum will start to experiment with solutions for mitigating impact.