This post is by Chris Stone, Environmental Test Manager at TRaC.
I’m meeting more and more engineers whose equipment is being subjected to earthquake testing. Even in the UK there is a risk of earthquakes; there is even a page tracking recent seismic activity on the British Geological Survey‘s website.
Although our earthquakes are pretty low down the Richter scale, they generally have significant energy content at the higher frequencies (10 to 40Hz) in critical applications where failure can be disastrous (e.g. nuclear power plant) or expensive (e.g. telecommunications equipment that must achieve “five 9s” uptime), earthquake testing makes sense.
Safety considerations and demands for higher reliability are not the only factors that are increasing the need for testing. Engineers are also realising that modelling seismic response is often not sufficient for electronic/electrical systems.
Modelling will predict if a structure can withstand an earthquake, but will give no guarantee of continued operation during or after a seismic event.
So, the best decision for many companies is to bring their equipment for a good shake on our earthquake table – you can see a video of a typical test.
Many products which have traditionally undergone standard vibration testing are now also being specified against earthquake tests, as the characteristics of the two tests are significantly different – something I discussed in our last blog post.