At the 40m we have some large Wilcoxon accelerometers: The 731A, low frequency, low noise ones. attachment:datasheet.pdf
Should we get some more? Probably. Would be good to have a 3-axis set at each end. But which kind?
The [http://www.endevco.com/product/Product.aspx?product_id=105 Endevco 86] looks good (see attachment:datasheet86.pdf). Need to get a price.