Coupling the acoustic emission probe with the specimen is the key link in the measurement of preexisting stress of the rock specimen by Kaiser effect.
以凯瑟效应测量岩石试样先存应力，声发射探头与试样的耦合是其重要环节。
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This can be done by directly coupling the device to the unit via the interfaces 58 and 80 or use can be made of another technique such as a short range radio frequency or infrared link.