FORFARANDE OCH ANORDNING FOR ATT FASTSTELLA BESKAFFENHETEN AV EN BERG- ELLER STENVOLYM SAMT HALLFASTHETEN AV DERI INFESTADE FESTELEMENT SASOM BERGBULTAR

摘要

In order to determine the properties of a rock or stone volume as regards lock up or hardness, a mechanical jolt is exerted against the volume and a sensor (11) is used to determine if primarily low or primarily high frequency waves are generated. The device for executing the procedure includes for this purpose an electronic circuit (200) with a frequency analyser circuit. The invention is particularly suitable for underground mining if there are loose blocks next to tunnels or the like. It can be especially used to determine if rock bolts are needed and/or if they are properly fastened.