Testing is well underway for arguably one of GDS’ most advanced products, the Acoustic Emission (AE) System. The piezo-electric AE sensors enable micro-fractures occurring within a rock specimen during testing to be recorded. As well as the number and frequency of the recorded micro fractures they can also be traced back to each of their origination positions and plotted on a 3D image of the sample. This is useful to track failure modes within the sample. The transducers are currently being tested on a Cobourg limestone sample in our 2MN, 64MPa high pressure triaxial cell.
There are two different acquisition systems available, one uses a continuous acquisition system and the other a triggered system. The triggered system derives less but more focused data to interpret whereas the continuous system can record huge amounts of data in great detail. With data acquisition speeds up to 50MHz and bit counts up to 16Bit there is a wide range available from GDS.
The GDS AE sensors can work in Passive mode for acquiring AE signals but also in Active mode where each sensor can be energised to produce a signal. The relative arrival time at each of the other sensors can then be determined (either manually or automatically). By compositing the data from each sensor a velocity based tomographic image of the sample can be constructed.
For more details, please visit www.gdsinstruments.com